Radio Shack Hardware Manual Color Computer Disk System Owners 1981 Tandy Text

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Owners Manual &Programming Guide

CUSTOM MANUFACTURED IN U.S.A. BY RADIO SHACK, ADIVISION OF TANDY CORPORATION

Important Notice: Your computer must be off when you connect the

disk interface. Otherwise, you could damage the system.

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TERMS AND CONDITIONS OF SALE AND LICENSE OF RADIO SHACK COMPUTER EQUIPMENT AND SOFTWARE

PURCHASED FROM ARADIO SHACK COMPANY-OWNED COMPUTER CENTER. RETAIL STORE OR FROM A

RADIO SHACK FRANCHISEE OR DEALER AT ITS AUTHORIZED LOCATION

LIMITED WARRANTY

CUSTOMER OBLIGATIONS

A. CUSTOMER assumes full responsibility that this Radio Shack computer hardware purchased (the "Equipment"), and any copies ot Radio

Shack software included with the Equipment or licensed separately (the "Software") meets the specifications, capacity, capabilities,

versatility, and other requirements of CUSTOMER.

BCUSTOMER assumes full responsibility for the condition and effectiveness of the operating environment in which the Equipment and Software

are to function, and for its installation

II. RADIO SHACK LIMITED WARRANTIES AND CONDITIONS OF SALE

A. For aperiod of ninety (90) calendar days from the date of the Radio Shack sales document received upon purchase of the Equipment, RADIO

SHACK warrants to the original CUSTOMER that the Equipment and the medium upon which the Software is stored is free from manufacturing

defects. THIS WARRANTY IS ONLY APPLICABLE TO PURCHASES OF RADIO SHACK EQUIPMENT BY THE ORIGINAL CUSTOMER FROM

RADIO SHACK COMPANY-OWNED COMPUTER CENTERS, RETAIL STORES AND FROM RADIO SHACK FRANCHISEES AND DEALERS AT ITS

AUTHORIZED LOCATION. The warranty is void if the Equipment's case or cabinet has been opened, or if the Equipment or Software has been

subjected to improper or abnormal use. If amanufacturing defect is discovered during the stated warranty period, the defective Equipment

must be returned to aRadio Shack Computer Center, aRadio Shack retail store, participating Radio Shack franchisee or Radio Shack dealer

for repair, along with acopy of the sales document or lease agreement The original CUSTOMER'S sole and exclusive remedy in the event of

adefect is limited to the correction of the defect by repair, replacement, or refund of the purchase price, at RADIO SHACK'S election and sole

expense. RADIO SHACK has no obligation to replace or repair expendable items.

B. RADIO SHACK makes no warranty as to the design, capability, capacity, or suitability for use of the Software, except as provided in this

paragraph. Software is licensed on an "AS IS" basis, without warranty. The original CUSTOMER'S exclusive remedy, in the event of a

Software manufacturing defect, is its repair or replacement within thirty (30) calendar days of the date of the Radio Shack sales document

received upon license of the Software, The defective Software shall be returned to aRadio Shack Computer Center, aRadio Shack retail store,

participating Radio Shack franchisee or Radio Shack dealer along with the sales document.

C. Except as provided herein no employee, agent, franchisee, dealer or other person is authorized to give any warranties of any nature on behalf

of RADIO SHACK.

D. Except as provided herein, RADIO SHACK MAKES NO WARRANTIES, INCLUDING WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A

PARTICULAR PURPOSE.

E. Some states do not allow limitations on how long an implied warranty lasts, so the above limitation(s) may not apply to CUSTOMER.

III. LIMITATION OF LIABILITY

A. EXCEPT AS PROVIDED HEREIN, RADIO SHACK SHALL HAVE NO LIABILITY OR RESPONSIBILITY TO CUSTOMER OR ANY OTHER PERSON

OR ENTITY WITH RESPECT TO ANY LIABILITY, LOSS OR DAMAGE CAUSED OR ALLEGED TO BE CAUSED DIRECTLY OR INDIRECTLY BY

"EQUIPMENT" OR "SOFTWARE" SOLD, LEASED, LICENSED OR FURNISHED BY RADIO SHACK, INCLUDING, BUT NOT LIMITED TO. ANY

INTERRUPTION OF SERVICE, LOSS OF BUSINESS OR ANTICIPATORY PROFITS OR CONSEQUENTIAL DAMAGES RESULTING FROM THE

USE OR OPERATION OF THE "EQUIPMENT" OR "SOFTWARE". IN NO EVENT SHALL RADIO SHACK BE LIABLE FOR LOSS OF PROFITS, OR

ANY INDIRECT, SPECIAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF ANY BREACH OF THIS WARRANTY OR IN ANY MANNER

ARISING OUT OF OR CONNECTED WITH THE SALE, LEASE, LICENSE, USE OR ANTICIPATED USE OF THE "EQUIPMENT" OR "SOFTWARE".

NOTWITHSTANDING THE ABOVE LIMITATIONS AND WARRANTIES, RADIO SHACK'S LIABILITY HEREUNDER FOR DAMAGES INCURRED BY

CUSTOMER OR OTHERS SHALL NOT EXCEED THE AMOUNT PAID BY CUSTOMER FOR THE PARTICULAR "EQUIPMENT" OR "SOFTWARE"

INVOLVED.

B. RADIO SHACK shall not be liable for any damages caused by delay in delivering or furnishing Equipment and/or Software.

C. No action arising out of any claimed breach of this Warranty or transactions under this Warranty may be brought more than two (2) years

after the cause of action has accrued or more than four (4) years after the date of the Radio Shack sales document for the Equipment or

Software, whichever first occurs.

D. Some states do not allow the limitation or exclusion of incidental or consequential damages, so the above limitation(s) or exclusion(s) may

not apply to CUSTOMER.

IV. RADIO SHACK SOFTWARE LICENSE

RADIO SHACK grants to CUSTOMER anon-exclusive, paid-up license to use the RADIO SHACK Software on one computer, subject to the following

provisions:

A. Except as otherwise provided in this Software License, applicable copyright laws shall apply to the Software.

B. Title to the medium on which the Software is recorded (cassette and/or diskette) or stored (ROM) is transferred to CUSTOMER, but not title to

the Software.

C. CUSTOMER may use Software on one host computer and access that Software through one or more terminals if the Software permits this

function.

D. CUSTOMER shall not use, make, manufacture, or reproduce copies of Software except for use on one computer and as is specifically

provided in this Software License. Customer is expressly prohibited from disassembling the Software.

E. CUSTOMER is permitted to make additional copies of the Software only for backup or archival purposes or if additional copies are required in

the operation of one computer with the Software, but only to the extent the Software allows abackup copy to be made. However, for

TRSDOS Software, CUSTOMER is permitted to make alimited number of additional copies for CUSTOMER'S own use.

F. CUSTOMER may resell or distribute unmodified copies of the Software provided CUSTOMER has purchased one copy of the Software for each

one sold or distributed. The provisions of this Software License shall also be applicable to third parties receiving copies of the Software from

CUSTOMER.

G. All copyright notices shall be retained on all copies of the Software.

V. APPLICABILITY OF WARRANTY

A. The terms and conditions of this Warranty are applicable as between RADIO SHACK and CUSTOMER to either asale of the Equipment and/or

Software License to CUSTOMER or to atransaction whereby RADIO SHACK sells or conveys such Equipment to athird party for lease to

CUSTOMER.

B. The limitations of liability and Warranty provisions herein shall inure to the benefit of RADIO SHACK, the author, owner and/or licensor of the

Software and any manufacturer of the Equipment sold by RADIO SHACK.

VI. STATE LAW RIGHTS

The warranties granted herein give the original CUSTOMER specific legal rights, and the original CUSTOMER may have other rights which vary

from state to state.

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The FCC wants you to know:

This equipment generates and uses radio frequency energy. If it is not installed and used properly,

that is, in strict accordance with the manufacturer's instructions, it may cause interference to radio

and television reception. It has been type tested and found to comply with the limits for aClass B

computing device in accordance with the specifications in Subpart Jof Part 15 of FCC Rules, which

are designed to provide reasonable protection against such interference in aresidential installa-

tion. However, there is no guarantee that interference will not occur in aparticular installation. If

this equipment does cause interference to radio or television reception, which can be determined by

turning the equipment off and on, the user is encouraged to try to correct the interference by one

or more of the following measures:

•reorient the receiving antenna

•relocate the computer with respect to the receiver

•move the computer away from the receiver

•plug the computer into adifferent outlet so that computer and receiver are on different branch

circuits.

If necessary, the user should consult the dealer or an experienced radio /television technician for

additional suggestions. The user may find the following booklet prepared by the Federal Commu-

nications Commission helpful: How to Identify and Resolve Radio-TV Interference Problems. This

booklet is available from the United States Government Printing Office, Washington, DC 20402,

Stock No. 004-000-0035-4.

TRS-80 Disk Extended Color

1981 Tandy Corporation and Microsoft.

The system software in the disk system is retained in aread-only

memory (ROM) format. All portions of this system software,

whether in the ROM format or other source code format, and the

ROM circuitry, are copyrighted and are the proprietary and trade

secret information of Tandy Corporation and Microsoft. Use,

reproduction, or publication of any portion of this material, with-

out the prior written authorization by Tandy Corporation, is

strictly prohibited.

Color Computer Disk System:

Fort Worth, Texas 76102, U.S.A.

Reproduction or use, without express written permission from

Tandy Corporation, of any portion of this manual, is prohibited.

While reasonable efforts have been taken in the preparation of the

manual to assure its accuracy, Tandy Corporation assumes no

liability resulting from any errors or omissions in this manual or

from the use of the information obtained herein.

Printed in the United States of America

10 98765432

WHYADISKIS FAST

Adisk is for storing your information. The precise

term for it is a"mini-diskette," but in this book we'll

just call it adisk. It is far superior to tape, the other

alternative.

Adisk is especially designed to "file" your infor-

mation so the Computer can immediately get the

information you want. For you, this means storing

and retrieving information —which takes along

time on tape —now can be done quickly and

efficiently.

ABOUT THIS BOOK

This book shows how to read and write on adisk. When

we wrote it, we had three different groups of people in

mind.

The first group includes all of you accomplished Radio

Shack programmers. We are referring, of course, to

those of you who learned to program by reading Getting

Started with Color BASIC and Going Ahead with

Extended Color BASIC. You'll find Sections Iand II of

this book another delightful experience. If you're espe-

cially ambitious, you'll also enjoy Section III.

How about those of you who have never programmed

and intend to use application programs written by

Radio Shack or someone else? You're the second

group. Read Chapter 1, "To Get Started." Then, if you're

interested in and want to take full advantage of your

disk system, go on to Section I, "The Disk." You don't

need to know anything about programming to under-

stand it.

If you don't belong to either of these two groups, you

probably already know how to program disk systems.

Read Chapter 1first to find out how to connect your sys-

tem. Then, go straight to the "BASIC Summary" at the

end of the book. Everything is summarized there with

page number references, for the things you want to read

more about.

TABLE OF CONTENTS

Chapter II To Get Started 1

SECTION I. The Disk

Chapter 21 Meet Your Disk 7

Chapter 31 AGarbled Up Disk 13

Chapter 41 You're the Boss 19

SECTION II. The Disk Program

Chapter 51 One Thing at aTime 25

(Sequential Access to aFile)

Chapter 61 Changing It All Around 29

(Updating aSequential Access File)

Chapter 71 AMore Direct Approach 33

(Direct Access to aFile)

SECTION III. The Refined Disk Program

Chapter 81 How Much Can One Disk Hold? 41

(What the Computer Writes in aDisk File)

Chapter 91 Trimming the Fat Out of Direct Access 47

(Formatting aDirect Access File)

Chapter 101 Shuffling Disk Files 53

(Merging Programs, Using Many File Buffers)

Chapter 111 Technical Information 57

(Machine-Language Input/Output)

Appendixes

Appendix Al Programming Exercise Answers 64

Appendix Bl Chapter Checkpoint Answers 66

Appendix CI Sample Programs 68

Appendix Dl ASCII Character Codes 79

Appendix El Memory Map 81

Appendix Fl Specifications 82

Appendix Gl Error Messages 83

Appendix HI BASIC Summary 85

TO GET STARTED

Before you install your Disk System, you need to

connect your Color Computer to the T.V. If you

haven't done it yet, refer to the Color Computer

Operation Manual.

A. CONNECT DISK SYSTEM

Your Disk System is easy to connect. Do it

before you turn on your Computer by simply

plugging in all the parts:

Note: the dotted lines represent tke connection of additional add-on drive

TO GET STARTED

1. Connect the Disk Interface to the plug

in the opening of your Computer.

IMPORTANT NOTICE: YOUR COM-

PUTER MUST BE OFF WHEN YOU

CONNECT THE DISK INTERFACE.

OTHERWISE, YOU COULD DAMAGE

THE SYSTEM.

2. Connect Plug Aof the Disk Cable to the

Disk Interface.

Connect Plug Bof your Disk Cable to

the plug on back of your Disk Drive.

Plug in the power cord to astandard

(120 V) electrical outlet.

If You Have Additional

Disk Drives

If you have more than one disk drive, do

step 3differently. Connect the 26-3023

Drive to the inside plug (Plug B). If you

have more 26-3023 Drives and an expanded

cable, connect these Drives to inside plugs

also. The 26-3029 Drive must be connected

to the last plug in the series.

You'll also need to number your Drives.

Number them from the inside out. starting

with Drive 0. The Drive connected to Plug

Bis drive number 0, the Drive connected to

Plug Cis drive number 1,etc.

B. POWER IT UP

Since your Disk System has several parts, you

need to turn ON several buttons to power-up

the entire system;

•Turn ON your television set.

•Select Channel 3or 4.

•Set the antenna switch on the TV. to

COMPUTER.

•Turn ON the Computer. (The power but-

ton is on the back left-hand side of your

keyboard.)

TO GET STARTED

•Turn ON the Disk Drives. (The power

buttons are on the rear.)

Have you turned ON all the buttons? This

message should appear on your screen:

DISK EXTENDED COLOR BASIC v.r,

UNDER LICENSE FROM MICROSOFT

(v.r, is two numbers specifying which version

and release you have.)

If not, turn off the Computer, check your con-

nections, and power it up again.

C. INSERT ADISK

After powering the system up, you can insert

adisk. If you plan to go through Section I, use

the blank, unformatted disk which comes

with your disk system. Otherwise, you can

insert your "application program" disk, (If

you have more than one drive, insert, the disk

in drive 0).

•Open the DRIVE DOOR.

•Position the disk with the notch on top,

as we show in the picture above.

Gently insert the disk until it stops-

Close the DRIVE DOOR.

Note: You cannot use ablank disk until you "format"

it. The next chapter shows how.

Now that your system is connected and powered-

up, you're ready to begin. Begin what? Well, if you

want to know how to take full advantage of your

disk system, we'd like you to read Section I. You'll

find alot of helpful information there.

If you're in ahurry to run your application pro-

gram, that's O.K., too. But please read these

guidelines first. We want your disks to last along

time.

•When storing the disk, keep it in its storage

envelope

•Do not turn the system ON or OFF with the

disk in the drive.

•Keep disks away from magnetic fields

(transformers, AC motors, magnets, TVs,

radios, etc.)

Handle disks by the jacket only. Don't touch

any of the exposed surfaces, even to dust

them.

•Keep disks out of direct sunlight and away

from heat.

Avoid contamination of disks with cigarette

ashes, dust, or other particles.

Use afelt-tipped pen only to write on the

disk label.

•Store disks upright in avertical file.

Note: Your disk drives should be on the right side of

your television set.

IMPORTANT NOTE!

If you have an earlier model of the Color Computer, the disk system might cause

interference on your screen. If so, bring the computer to aRadio Shack Repair

Center for additional grounding connections. (There will be no charge for this

service.)

SECTION I

TMH2 BMK

Adisk is like afiling system. Everything on it is

organized.

This makes disks easy to work with. In this section,

we'll show you how your Computer organizes

everything on your disk, and how you can take

advantage of this.

We invite all of you to read this section. You don't

need to know anything about computers to under-

stand it.

MEET YOUR DISK

ALOOK INSIDE OF IT

Although your disk looks like arecord, it is really

more like amultitude of tiny magnets. One disk

can hold more than amillion magnetic charges.

1,290,240 of them are for your information. That's

what we mean when we say adisk will hold

1,290,240 bits or 161,280 bytes of information

(there are eight bits in abyte).

Some of these bits are magnetically charged and

some aren't. The pattern formed by these mag-

netic charges is what's important. It forms a code

which the Computer can read.

With more than amillion of these bits on adisk,

you can appreciate how your Computer must orga-

nize them in order to find anything. It does this by

building amassive disk filing system. First it cre-

ates the file cabinets by dividing your disk into

"tracks." Then it puts drawers in the cabinets by

dividing each track into "sectors" Then ...we're

not finished yet .. . each sector is divided into bytes

and each byte is divided into bits.

Note: To be precise, there are 35 tracks on adisk, 18

sectors in each track, 256 bytes in each sector, and 8

bits in each byte.

;

After creating this filing system, the Computer

puts amaster directory on the disk. There, it

indexes where everything is stored. Whenever it

wants to find something —aprogram, amailing

list, your letters —it uses the directory to find the

tracks and sectors where it is stored. It can then

go directly to that spot.

This whole filing system is, of course, what makes

the disk system so powerful. You can quickly find

anything you have stored on your disk.

Putting this filing system on your disk is called

"formatting" it. The last thing we had you do in

Chapter 1was to insert an "unformatted" disk.

Before you can use it, you must format it into

tracks and sectors.

FORMATTING ADISK

How do you format adisk? Well .. . why not just tell

your Computer to do it? If you went through the

MEET YOUR OISK

instructions in the last chapter, you have already

powered-up your system and inserted an "unfor-

matted" disk. Be sure you have your DRIVE

DOOR closed.

Now, type any letters and press the (ENTER) key so

that:

is the last line on your screen. (OK means "OK,

I'm ready to do something") Now type what you

want it to do. Type:

DSKINI0

and press the CENTER) key. Your Computer might

print ?SN ERROR. If so, don't let this bother you.

This "error" simply means you typed the com-

mand incorrectly. Type it again.

Whenever anything goes wrong, the Computer

will let you know immediately with an error mes-

sage. This way you can correct the error right

away. If you get any other error message besides

SN, look it up in Appendix G. It lists all the error

messages and what to do about them.

After typing DSKINI0 (ENTER), you'll hear some

noises from your disk drive and its red light will

come on. Sounds promising . .

After about 40 seconds of noises, your Computer

will then print OK. It has finished formatting the

disk. You can now store your information.

Remember that you cannot store anything on an

unformatted disk. Whenever you get anew, unfor-

matted disk, you need to format it before you can

use it.

Later on, you might not remember if adisk has

been formatted. Aquick way to find out is to check

the directory. (See "Checking the Master Direc-

tory" at the end of this Chapter.) If you get an

"error message'' the disk is not formatted.

Note: It does no harm to reformat a disk. Thin

common way to erase everything on it.

If you have more than one disk drive, you can for-

mat adisk in one of the other drives by substitut-

ing the appropriate drive number for drive 0. For

example, DSKINI1 formats the disk in drive 1.

PUTTING AFILE ON YOUR DISK

Adisk file can contain any kind of information —

aprogram, amailing list, an essay, some checks.

We'll make your first file contain aBASIC pro-

gram, since it's the simplest thing to store.

If you don't know how to program in BASIC, type

this program anyway. Type each line exactly as it

is shown below. Press the (ENTER) key after typing

each line. Type:

10 PRINT "STORE ME IN ADISK FILE" (ENTER)

20 PRINT "AND YOU'LL NEUER LOSE ME" (ENTER]

Finished? Now that you've typed the program into

your Computer's "memory," you can put it on a

disk. To do this, we'll call it afile and name the file

"SIMPLE/PRO" (all files have aname). To store it,

type:

SAME "SIMPLE/PRO" [ENTER)

Once you press the (ENTER) key, your disk drive will

whirr and grind some and the red light on it will

come on. Your Computer is:

•finding aplace on the disk to store "SIMPLE/

PRO"

•telling the directory where "SIMPLE/PRO" will

be stored.

•storing "SIMPLE/PRO" on your disk.

Note: The Computerstores "SIMPLEPRO" the same

way it stores everything else —in a code of magnetic

charges.

At this point, we must warn you about something.

Do not remove your disk while you see the red

light on. This confuses the Computer. It might dis-

tort the contents, not only of the file you are pres-

ently storing, but of other things you have stored

on the disk.

When your Computer finishes storing "SIMPLE/

PRO," it prints the OK message on your screen.

MEET YOUR DISK

Note: Upgrading your tape system? Note the differ-

ence: SAVE stores aprogram on disk; CSAVE stores

it on tape I

RUN CENTER)

MEMORY VS DISK STORAGE

To those of you new to computers, we would like to

expound alittle on computer "memory." If you

already know what it is, skip down to the next

heading —"Loading aFile from Disk!'

Whenever you type aBASIC program line and

press (ENTER) ,the Computer automatically puts it

in its memory. Once it's in memory, you can do

things with it. For example, type:

RUN [INTER]

Your Computer PRINTs:

STORE ME IN ft DISK FILE

AND YOU'LL NEVER LOSE ME

To list the program as you have it above, type:

LIST dNTEFD

Memory is where the Computer keeps track of

everything you tell it. Once you put your infor-

mation in its memory, the Computer can print it,

rearrange it, combine it, or any of the other things

you want done with it.

Later on, you'll probably want to put other things,

such as your mailing list, in memory. To do this,

you'll need to write or purchase aprogram written

especially for that application. This "application

program" will get the Computer to put the infor-

mation you type into memory.

The important thing to remember about memory

is that turning off your Computer erases it. Once

memory has been erased, there's no way to recover

it. The only way to keep apermanent copy of what

you've typed into memory is by storing it on adisk

(or tape).

LIST [ENTER)

Although NEW erased the program from memory,

"SIMPLE/PRO" is still safely stored on your disk.

You can put "SIMPLE/PRO" back into memory

anytime you want by "loading" it from disk. To do

this, type LOAD "SIMPLE/PRO" [ENTER] .

Again, you'll hear some promising noises from

your disk drive. The Computer is:

•reading the directory to find where "SIMPLE/

PRO" is stored.

going to that location on the disk and reading the

contents of "SIMPLE/PRO."

•putting "SIMPLE/PRO" into its memory.

You can now type one or both of these commands

to verify that "SIMPLE/PRO" is in memory:

LIST (ENTER)

RUN (ENTER)

LOADING AFILE FROM DISK

Type NEW [ENTER) to erase everything in your Com-

puter's memory. To make sure everything's erased,

you can type one or both of these commands:

MORE ABOUT MEMORY VS DISK

STORAGE

If you're still alittle fuzzy about what's in memory

and what's on your disk, try this exercise. You've

MEET YOUR DISK

just LOADed aprogram called "SIMPLE/PRO"

into memory, right? Change it by typing:

20 PRINT "WITH THIS CHANGE" (ENTER]

LIST the program again to see that the Computer

has registered the changed line 20 in its memory:

10 PRINT "STORE ME IN ADISK FILE"

20 PRINT "WITH THIS CHANGE"

Store it in adifferent file by typing SAME

"CHANGE" [ENTER) ...

Hear the whirring and grinding from your disk

drive? You have two disk files now: "SIMPLE/

PRO" and "CHANGE" What do you think each of

them contains? Try LOADing and then LISTing

both of them.

[Note: You don't need to type NEW (EBTER] before LOAD-

ing anew program into memory. The Computer will

automatically erase everything you presently have in

memory before LOADing the new program.

??????????????????????????????????????????????????

"CHANGE" contains the changed program:

10 PRINT "STORE ME IN ADISK FILE"

20 PRINT "WITH THIS CHANGE"

However, "SIMPLE/PRO" still contains the old

program:

10 PRINT "STORE ME IN ADISK FILE"

20 PRINT "AND YOU'LL NEUER LOSE ME"

NEW [INTEH]

10 PRINT "CHANGED FILE" (ENTER]

SfliJE "SIMPLE/PRO" (ENTER)

FILENAMES

You have already used one filename:

"SIMPLE/PRO"

If you did our memory vs. disk storage exercise,

you've used asecond filename:

"CHANGE"

We gave the name "SIMPLE" an "extension" —

"PRO." You must give everything you store a

name. The extension is up to you. It's optional.

What names can you give your files? Anything

you want, as long as you follow these rules:

1. The name may have no more than eight

characters.

2. If you give it an extension, the extension may

have no more than three characters.

3. There must be aslash (/) or aperiod (.) between

the name and the extension.

Fair enough? Good.

Note: You may use any characters in the filename

except acolon (:) or a zero (0). You can only use a

slash (I) or aperiod (.) to separate the name from th

extension.

The only way to change adisk file is by ...well,

you answer it. How can you make the file "SIM-

PLE/PRO" contain:

10 PRINT "CHANGED FILE"

??????????????????????????????????????????????????

Answer:

T>pe:

FILENAMES WHEN YOU HAVE

MORE THAN ONE DRIVE

If you have more than one disk drive, you can add

the drive number to your filename. (Remember,

you numbered all of your drives in Chapter 1), For

example:

LOAD "SIMPLE/PRO:!"

MEET YOUR DISK

LOADs "SIMPLE/PRO" from the disk in drive

number 1. Or

SAVE "CHANGE:1"

stores "CHANGE" on the disk in drive number 1.

If you don't include adrive number, the Computer

assumes you want it to use drive number 0.

CHECKING THE MASTER

DIRECTORY

As we've said earlier, adisk has amaster directory

which the Computer can use to find out what's on

the disk. If the Computer can use it, you can use

it, too. TypeDlR tEHTEH).

The Computer prints information on all the files

you have stored on your disk. If the only files

you've stored so far are "SIMPLE/PRO" and

"CHANGE," the Computer prints this:

SIMPLE

CHANGE

PRO

BAS

The first and second columns list the filename.

The first is the name and the second is the exten-

sion. Notice that even though you did not assign

"CHANGE" an extension when you stored it, the

Computer still assigned it the extension "BAS."

The Computer prefers for all filenames to have an

extension. If you do not give a file an extension

when you store it, the Computer will automati-

cally assign one of these extensions:

"BAS" if it's aBASIC program

"DAT" if it's data (such as names, numbers, etc.)

"BIN" if it's amachine-language program)

Note: Amachine-language program is ahighly tech-

nical program which talks directly to the Computer.

The next three columns contain information

which is primarily for the use of technical pro-

grammers. Interested? Then read on ..

The third column lists the type of file it is:

BASIC program

1data created by aBASIC program

2data created by amachine-language program

3asource program created by an editor/

assembler

Note: An eriitnrtasxembler ix aprogram you can buy

to help you create amachine-language program.

The fourth column lists the format the file is

stored in:

AASCII

BBinary

We'll explain the meaning of this in Chapter 10.

The fifth column shows how many "granules" each

file consumes. "SIMPLE/PRO" and "CHANGE/

BAS" consume one granule each. (The Computer

uses "granules" to allocate file space on adisk. A

disk contains 68 of these "granules").

If you have disks inserted and formatted in other

drives, you can check their directories also. For

instance DIRl fjNTEl) displays the directory of the

disk in drive number 1.

Impressed? You'll be even more impressed when

you see how fast you can SAVE and LOAD long

programs. But before you get too involved, please

read the next chapter. It'll help ensure that your

experience with your Disk System is smooth and

enjoyable.

Note: To stop the directory from scrolling, press the

SHIFT) and (W) keys simultaneously. Then press

MB®.

CHAPTER CHECKPOINT

1. Why can't you store things on an unformat-

ted disk?

2. What is the disk's directory?

3. What is adisk Sle?

4. What is the difference between what's in

memory and what's on the disk?

5. How do you change the contents of adisk

Sie?

Do you like quizzes? The answers are in

Appendix B.

AGARBLED UP DISK

With more than amillion magnetic charges on a

disk, you can see why it is so delicate. Any small

particle such as a piece of dust or acigarette ash

could distort its contents. Ascratch could ruin it.

That's why we suggest that you keep the disk in

its envelope when you're not using it —preferably

upright in adust-free container —and only use a

felt-tipped pen when labeling it.

To help protect the disk, we encased most of it in

ablack plastic container. However, as you can see,

we weren't able to cover the entire disk. The mid-

dle section and two other small areas are exposed

so the Computer can read and write to it. Be care-

ful not to touch the exposed areas, not even to dust

them. They scratch very easily.

Since the disk is made up of magnetic charges,

putting it next to another magnetic device, such as

your television set, could completely rearrange its

magnetic code. Your information would be lost.

Heat and sunlight could have the same effect. The

same goes for turning your Computer ON or OFF

while the disk is in its drive.

One more thing ... If you're in the middle of run-

ning adisk program, and need to switch disks, we

recommend that you type this command:

UNLOAD fIRTER)

before you switch disks. This way the Computer

can put its closing information on the proper disk.

If you don't type this command, the Computer

might put this information on the wrong disk and

garble the contents of both disks.

Note for BASIC programmers;All open files must

be closed before switching disks, UNLOAD closes al,

open files.

BACK IT UP

All of this might sound alittle gloomy to you, even

if you are a careful person. This is why we've

included acommand called BACKUP. BACKUP

will enable you to make aduplicate or "backup"

copy of any of your disks by copying the contents

of one disk to another.

AGARGLED UP DISK

We suggest you regularly make abackup copy of

any disk which contains important programs or

data. This way you won't have to worry about los-

ing them.

Also, since adisk can actually get worn out from

too much use, it's agood idea to make abackup

copy of an old disk on anew, unused disk. Then,

when the Computer begins having its problems

reading and writing to the disk, you can use your

backup copy.

Want to make abackup copy? Get your two disks

ready:

1. Your "source" disk —This is the disk you want

to duplicate. Use any disk which has files stored

on it. If you're just getting started, use the disk

which you worked with in Chapter 2.

2. Your "destination" disk —This is the disk which

you want to be your duplicate copy. Use ablank

disk or, if you've been using your disk system

for awhile, use any disk which contains files

you won't need anymore.

After making some noise while it reads aportion

of your "source" disk, the Computer will print:

\'ote:Everything preciously on your destination dish

it- ill be erased. It will be replaced with all the data i

your source disk.

If your "destination" disk is blank, you must

first format it. Remember how? Insert it in your

disk drive, shut the door, and type DSKINio

CENTER) .

Now make the backup copy. The procedure you fol-

low depends on whether you have one disk drive

or several.

Backup with One Disk Drive

If you have only one disk drive, it will take you

about five minutes to make abackup copy. Insert

your "source" disk in your disk drive and shut the

DRIVE DOOR. Type OIR (ENTER) to see which files

you will be copying.

Now start the backup procedures. Type:

INSERT DESTINATION DISKETTE AND PRESS CENTER;

Take the "source" disk out and insert the "desti-

nation" disk. Shut the DRIVE DOOR. Then press

(ENTER). You'll hear some more noise while the

Computer "writes" some things on the "destina-

tion" disk. Then it will print:

INSERT SOURCE DISKETTE AND PRESS CENTER)

The Computer will have you continue switching

disks until you have copied everything from your

source disk. During this process, make sure you

insert the correct disk and insert it properly. When

you've finished, the Computer will print the OK

message on your screen.

To make sure BACKUP worked, you can insert

your "destination" disk and type DIR(ENTER) .

Backup with More Than One Disk

Drive

If you have more than one disk drive, backing up

adisk is much easier. It will take about two

minutes.

Insert your "source" disk in drive and your "des-

tination" disk in drive 1(Chapter 1shows how to

label your drives). Then type:

BACKUP CENTER)

BACKUP TO i(ENTER)

You will hear some noise as the Computer backs

up the contents of the disk in drive to the disk in

drive 1. When it's finished, it will print the OK mes-

sage. You can then make sure BACKUP worked

by typing DIRi CENTER) .

You can use different drives, if you want. For

instance:

BACKUP 1TO (INTER)

backs up the contents of the disk in drive 1to the

one in drive 0.

AGARBLED UP DISK

If You have Problems During

Backup

If you get an error message while you're backing

up adisk, it's probably because you've inserted the

disk incorrectly or there is something wrong with

the disk. At the end of this chapter, we discuss

error messages to help you determine the prob-

lem. If you have abad disk, you will need to try

BACKUP with another disk.

After determining the problem, press the RESET

button to get out of BACKUP. Then start the

BACKUP procedure all over again.

Note: The RESET button is ore the right-hand rear

ofyour Computer (when you're facing it).

"WRITE" PROTECT IT

"Write-protecting" is one more way to protect your

disk files. Let's assume you have adisk which con-

tains some valuable information —such as agood

program —which you don't plan to change. You

plan to "read" its contents daily, by loading the

program into memory, yet you never plan to

"write" (store information) on it.

Putting alittle gummed label on the WRITE-

PROTECT NOTCH will enable the Computer to

read the disk, but not to write on it. Any gummed

label will do. There is one which comes with your

new, unformatted disk:

SALVAGE IT

We mentioned earlier that a disk doesn't live for-

ever. Before you throw away an old disk, though,

see if you can salvage it. You may be able to do this

by formatting it all over again as if it were ablank

disk.

Although this might salvage the disk, it will not

salvage the contents of the disk. By reformatting

the disk, you will erase everything on it. However,

it will save you the expense of purchasing anew

disk.

If you get an 10 error while trying to reformat it

(see "Error Messages" at the end of this chapter),

the disk has probably reached its limit. If you have

a"bulk-eraser," you can try "bulk-erasing" the

disk and reformatting it. Otherwise, throw it

away and use another one.

Note:Ifyou have more than one disk drive, you might

be able to COPY some of the files on a bad disk to a

good disk. We discuss COPY in the next chapter.

VERIFY IT

The Computer "writes" data on your disk at avery

fast speed. In almost all cases, it can do this

flawlessly.

There might be times when you want to be abso-

lutely certain that there are no flaws in what the

Computer is writing. If so, you can turn ON the

Computer's VERIFY command. To do this, type:

VERIFY ON (ENTER)

Now the Computer will notify you, whenever it is

writing on adisk, if there are any flaws in what it

is writing. The only catch is that it will take twice

as long for the Computer to write.

For example, let's assume you now make a

BACKUP copy of your disk. The Computer will

take twice as long doing this, but will notify you

if there is aflaw in the BACKUP copy.

This VERIFY command will remain ON until you

turn it off. To do this, type:

VERIFY OFF (ENTER)

AGARBLED UP DISK

WHEN THINGS GO WRONG

Your Computer realizes nobody's perfect. When

you make amistake, it'll try to notify you imme-

diately and tell you what kind of "error" you

made.

You've probably already been notified that you

made a"SN ERROR." If you haven't, type DIIR

[ENTER) deliberately mispelling DIR.

SN means "Syntax" error. It's the Computer's way

of telling you that "DIIR" doesn't make sense to it.

The word is not in its vocabulary. An SN error

usually means you made atypographical error.

Here are some other error messages you're likely

to get with your disk system:

AE —You are trying to RENAME afile (discussed

in the next chapter) to afilename which

Already Exists.

DF —The Disk you are trying to store your file on

is Full. Use another disk.

DN —You are using aDrive Number higher than

3. You will also get this error if you do not

specify adrive number when using DSKINI

or BACKUP. If you have only one drive

specify drive with these two commands

(DSKINIO or BACKUP 0)

FN —You used an unacceptable format to name

your file. The last Chapter explains which

File Names are acceptable to the Computer.

FS —There is something wrong with your disk

file. See 10 for instructions on what to do.

/0 —Technically, this means you have asked the

Computer to divide anumber by 0, which is

impossible. However, you might also get

this error when you don't enclose afilename

in quotation marks.

10 —The Computer is having trouble Inputting

or Outputting information to the disk.

(1) Make sure there is adisk inserted

properly in the indicated drive and the

drive door is closed.

(2) If you still get this error, there might

be something wrong with your disk.

Try reinserting the disk first. Then try

using adifferent one or reformatting

it. (Remember that reformatting a

disk erases its contents.)

(3) If you still get this error, you probably

have aproblem with the Computer

System itself. Call the Radio Shack

Repair Center.

NE —The Computer can't find the disk file you

want. Check the disk's directory to see if the

file is there. If you have more than one disk

drive, you might not have included the

appropriate drive number in the filename. If

you are using COPY, KILL, or RENAME

(discussed in the next chapter), you might

have left off the extension.

TM —Technically this is caused by aprogram

which mixes "strings" with "numbers."

However, you might get this error if you

don't enclose afilename in quotation marks.

UF —You will only get the error when you have

the VERIFY command ON and are writing

to adisk. The Computer is informing you

that there is aflaw in what it wrote. See 10

for instructions on what to do.

WP—You are trying to store information on adisk

which is Write Protected. Either take the

label off the write protect notch or use adif-

ferent disk. If your disk is not Write Pro-

tected, then there is an input/output prob-

lem. See 10 for instructions on what to do

about this.

All other errors you might get are errors in the

program you are using. If you did not write the

program and get one of these errors, you need to

contact the people who wrote it. If you did write it,

check Appendix G, where you'll find an explana-

tion of all the error messages.

AGARBLED UP DISK

Caring for your disk might seem alittle awkward

at first. It should. You've spent most of your life

protecting your papers and now you're dealing

with a different medium.

After awhile, though, protecting your disk from

dust and magnetic devices will seem as natural to

you as protecting your papers from a strong gust

of wind. And once you get used to keeping your

disk "ungarbled," you'll never want to go back to

pencils and paper again (we hope).

\Z CHAPTER CHECKPOINT

1. Why shouldn't you turn the Computer ON

or OFF while the disk is in its drive?

2. What type of pen can you use to write on

the disk's label?

3. What are error messages?

4. What does write-protect mean? How do

you do it?

5. How do you backup adisk?

YOU'RE THE BOSS

Thanks to your disk filing system, you are able to

command the Computer to do alot of very helpful

things. For example, you can rename afile. If

you've taken your formatted disk out, re-insert it.

Note: Can't remember if your disk's formatted?

Check the directory by typing DIB (EBBS) (or DIBB or

DIRi ifyou have more than one drive).

Type this to put afile on your disk:

10 PRINT "THIS IS AFILE" (ENTER)

SAVE "ORIGINAL/NAM" (ENTER)

Check the directory to see that the program file is

stored on your disk under the name ''ORIGINAL/

NAM" ...Now rename it. Type:

RENAME "ORIGINAL/NAM" TO "NEW/NAM" (ENTER)

Hear the disk drive working? Check your DIRec-

tory again. If you'd like, LOAD and LIST "NEW/

NAM." The program file has simply been renamed.

Everything else is the same.

RENAME is easy to use, but there is one thing you

need to remember. Save afile without an exten-

sion and then try to rename it. Type:

13 PRINT "FILE

IE "AFILE" (E

JAME "AFILE"

NUMESER TWO

BFILE"

'(ENTER)

Sfli NTER)

TO '

rei* (ENTER)

The Computer gives you an NE error. This means

the Computer can't find the file.

When you RENAME afile, you must type in the

complete name of the file so that the Computer can

find it. This includes the name and the extension.

As we discussed in Chapter 2, whenever you SAVE

afile the Computer will make sure it has an exten-

sion. If you don't assign it one, the Computer will.

You can check the directory to find out the exten-

sion of "AFILE." Then RENAME it. Type:

RENAME "AFILE/BAS" TO "BFILE/BAS" (ENTER)

If you're renaming aprogram file, be sure that

your new filename has an extension. In other

YOURE THE BOSS

words, don't type RENAME "AFILE/BAS" TO "BFILE"

[INTER) .The Computer would RENAME the file,

however "BFILE" would not have an extension.

This would cause aproblem when you try to

LOAD "BFILE," since all files you LOAD must

have an extension.

This might seem to conflict with what we said

above. You were able to SAVE "AFILE" without

assigning it an extension because the Computer

automatically assigned it one when it saved it.

RENAME works differently The Computer won't

automatically assign an extension to aprogram

you rename.

NotesThere is one way toLOAD "BFILE" wlthoutan

extension. This is by indicating that there Is no exten-

sion by typing LOAD "BFILE/" (ERIEE). This is awk-

ward. That's why we suggest, when renaming afile,

you always assign it an extension.

Multi-Disk Drives

You can RENAME afile on another disk drive,

simply by typing the appropriate drive number.

Insert a formatted disk in drive 1 {if it's not

already inserted). Store a file on it:

10 PRINT "ACCOUNTING" 1ENTER]

SAME "0LDACC/DAT:1" (INTER]

and RENAME it by typing:

RENAME "0LDACC/DAT:1" TO "NEWACC/DAT :1"

(enteB)

Nate: If you want your renamed file on adifferent

drive, you can't use RENAME. Use COPY. I

ALMOST OUT OF DISK SPACE?

Sooner or later, you'll want to know how much

space you have left on your disk. Type:

PRINT FREE(0) (ENTER]

The Computer prints the number of FREE "gran-

ules" remaining on your disk.

There are 68 granules in all. If the Computer tells

you that you have only one granule FREE, you'd

better do one of the following: start using another

disk or "KILL" some of your disk files.

KILLing adisk file does just what the name

implies. For example, if you put "CHANGE" on

your disk in Chapter 2, type:

KILL "CHANGE/BAS" (ENTER)

Check your directory and the FREE space remain-

ing on your disk. "CHANGE/BAS" is no longer on

your disk. The space it occupied is now FREE for

new files.

Notice, we had to include CHANGE'S extension,

"BAS" in order to KILL it. The Computer insists

you type the complete filename as one extra pre-

caution. It doesn't want to KILL afile you don't

want destroyed.

Note: Want to get very technical? The data will still

exist on the disk after you KILL afile. However, the

Computer won't know it's there because KILL deletes

all reference to it in the dish's directory. Therefore,

you'll no longer be able to access the data and the

Computer will be able to write over it with anew file.

Multi-Disk Drives

You can use FREE and KILL on other disk drives,

as you can with RENAME, by typing the drive

number. Examples:

PRINT FREE(l) INTER)

tells you how much FREE space is on the disk in

drive 1.

KILL "NEWACC/DAT: 1" (ENTER]

deletes "NEWACC/DAT" from the disk in drive 1.

SPECIAL MULTI-DRIVE

COMMANDS

In the rest of this chapter, we'll talk about two

commands which you can use if you have amulti-

drive system. If you don't have one, go on to

"Chapter Checkpoint" at the end of this chapter.

YOU'RE THE BOSS

The first one copies a disk file. You should, at this

point, have aprogram file stored in the disk in

drive named "NEW/NAM." Make aCOPY of it.

Type:

COPY "NEW/NAM:0" TO "NEW/NAM: 1" (ENTER).

If you want, you can rename the file when you

copy it. For instance, COPY "NEW/NAM :1" TO

"ANOTHER/NAM :0" (ENTER) copies "NEW/NAM"

from the disk in drive 1to the file "ANOTHER/

NAM" on the disk in drive 0.

The second command changes the drive number

the Computer goes to if you do not specify one. Up

to now, this has been drive 0. For example, by typ-

ing SAOE "ANYTHING/EX" (ENTER), the Computer

will assume you want to use drive 0. It will then

SAVE this program on the disk in drive 0.

To change this assumption, you can type:

DRIVE 1CENTER)

This makes the Computer assume you want it to

use DRIVE 1, unless you tell it otherwise.

After changing this DRIVE assumption, the Com-

puter will respond differently to the same com-

mand. By typing SAUE "ANYTHING/EX" (ENTER) ,the

Computer will store "ANYTHING/EX" on the

disk in drive 1. You would now need to type SAVE

"ANYTHING/EX :0" (ENTER] to SAVE it in drive 0.

CHAPTER CHECKPOINT

1. How do you rename afile? Why do you

have to specify the file's extension?

2. What can you do when you think you're

running out of disk space?

3. If you have more than one disk drive and

do not specify the drive number, which

drive will the Computer use? How can you

change this?

Congratulations. You are now a bonafide disk sys-

tem operator. You should now have agood under-

standing of how your disk system works and how

to take full advantage of it.

SECTION II

TTDDIE IMSBS IPMDCSIEA

Storing aBASIC program is easy. You only need to

use the SAVE command. Storing data takes alittle

more effort. You need aprogram.

Some of you might prefer to buy aready-made pro-

gram. However, if you want more control and are

willing to invest alittle time, you will enjoy writing

your own.

In this section, we'll show you how to write aBASIC

program which stores data on disk. We are assum-

ing you already know some BASIC. If you don't,

read Section Iof Getting Started with Color BASIC.

It will give you all the background you need.

ONE THING AT ATIME

(Sequential Access to aFile)

Atape is simple. There's only one way to put data

on it and one way to read it off. Adisk is more com-

plex. There are several ways to "file" your data on

it.

In this chapter and the next, we'll show how to

write aprogram which stores data in a"sequential

access" disk file. It's the simplest file to create and

is actually very similar to atape "file" In Chapter

7, we'll introduce "direct access," an alternate type

of disk file.

In showing how to store things on disk, we'll fre-

quently use the words disk file and disk directory.

We discussed these concepts in Chapter 2, but we'll

summarize them now.

Everything you store on disk must go in adisk file

and be assigned afilename. Your Computer will

index the location of the disk file in the disk's

directory. For example, if you want to store the

names of your friends, you could put them in a

disk file named "FRIENDS'' Your disk's directory

would then index where, on the disk, "FRIENDS"

is stored.

There is, of course, agood reason for all of this.

Using the disk filing system, the Computer will be

able to immediately find any file on the disk.

WRITING ADISK FILE

Let's assume you want to "write" your checks on

the disk:

CHECKS

DR. HORN

SAFEWAY

FIRST CHRISTIAN

OFFICE SUPPLY

Weil start with ashort, simple program which

writes the first check, "DR. HORN|' on the disk.

Insert aformatted disk in your disk drive. (If you

have more than one disk drive, use drive 0.)

ONE THING AT ATIME

Note: Chapter 2shows how to format adi-sk. (Type

DIB JN.TEE- ifyou can't remember whether adisk is for-

matted.) Chapter 1explains the drive numbers.

Then type:

10 OPEN "0"t *lr "CHECKS/DAT"

20 WRITE »1 t"DR. HORN"

38 CLOSE »1

RUN the program. You'll hear the motor of the

disk drive and see the red light. The Computer is

at work, doing several tasks.

First, it OPENs communication to the disk so you

can send your checks out to it. Then, it finds an

empty location to store the checks and notes the

beginning location of that disk file in the directory.

All of this happens in line 10. Notice the meaning

of the "O", #1, and "CHECKS/DAT":

1. #1 is aspecial "buffer" area in memory called

buffer #1. It communicates with the disk drive.

Line 10 OPENs this buffer. (If you've been

using tape, you might remember that buffer

•-1communicates with the tape recorder.)

2. "0" is the letter "O" not azero. It stands for out-

put. It tells the Computer that buffer #1 will be

sending out data to the disk.

3. "CHECKS/DAT" is the name of the disk file.

The disk's directory uses this name to index its

beginning and ending locations.

In line 20, the Computer sends out the words "DR.

HORN" to buffer #1 which WRITEs it on the disk.

Then, in line 30, the Computer CLOSEs commu-

nication with buffer #1. In doing this, it:

•sends out all the data remaining in buffer #1

to the disk file.

•notes in the disk's directory where "CHECKS/

DAT" ends.

Note: Abuffer temporarily stores data so the Com-

puter can input and output data to the disk in Mocks of

249 characters Ibytes) .Since buffer #1 only contains 8

characters ("DR .HORN"), they would not be sent out

to the dish without closing the file.

It is very important that you CLOSE communi-

cation with buffer #1. Why? Well, let's leave

buffer #1 OPEN. Delete line 30 and RUN the pro-

gram several times.

The program appears to work the same every time

you RUN it. This is because every time you RUN

(or LOAD) aprogram, the Computer will auto-

matically CLOSE communication with any buff-

ers you've left OPENed.

Now, let's assume you switch disks and RUN or

LOAD aprogram. The Computer will automati-

cally CLOSE communication with buffer #1. In

doing this, it will send out its closing information

to the new disk (thinking it's the old one). This

will very possibly garble the contents of both

disks.

Now that we've warned you of the importance of

line 30, re-insert this line in your program and

RUN it again. This is what the program writes on

your disk:

<cne Vys

*»r-

"DR. HORN"

Vote: Like our drawing of the disk? The en

"CHECKS/DAT" file consists of the words "DR

HORN'' The disk's directory notes the beginning and

ending locations of this file.

You can verify that the Computer has done this by

checking the disk's directory. You remember how

to do that. (Type DIR(ENTER))

Because this program sends your data out to the

disk file, we'll call it an output program.

READING THE DISK FILE

To get the Computer to read this data from the

disk back into its memory, you need an input pro-

gram. Erase the output program you now have in

NETHINGATA1

memory by typing NEW (ENTER) .Then type and RUN

this input program:

100 OPEN "I". #li "CHECKS/DAT"

110 INPUT #1 .A*

120 PRINT At

130 CLOSE #1

This is actually just the reverse of the output

program . .

Line 100 again OPENs communication to buffer

#1. This time communication is OPEN for "F —

input. The Computer goes to the disk's directory to

find where to start inputting the file named

"CHECKS/DAT"

In line 110, the Computer INPUTs the first data

item from the disk file named "CHECKS/DAT"

and labels it A$. Line 120 PRINTs A$.

Finally, line 130 CLOSEs communication to

buffer #1. In doing this, the Computer inputs any

data remaining in the buffer.

JVoie: You can compare an input program to the

LOAD command. An input program inputs adat<

file: LOAD inputs aprogram file.

©V

ONE CHECK AT ATIME

At this point, we've used an output program and

an input program. Let's combine them into one

program. Type:

10 OPEN "0" i*1 i"CHECKS/DAT"

20 WRITE *1 ."DR. HORN"

30 CLOSE #1

100 OPEN "I" t«li "CHECKS/DAT"

110 INPUT *1 ,A$

120 PRINT A*

130 CLOSE *1

Now add these lines and RUN the program:

25 WRITE *1 i"SAFEWAY"

115 INPUT «1 tB$

120 PRINT A$ tB*

Lines 10-30 output two checks into your disk file:

"DRHORNt" "SAFEWAY"

Lines 100-130 input them. Try to input more than

two checks. Change line 115 and 120:

115 PRINT A$

120 GOTO 110

and RUN the program ...The Computer prints:

?IE ERROR IN 110

The Computer is notifying you that you are asking

it to input more checks than are in the file.

Technically, the IE error means you've attempted

to Input past the End of the File.

This error makes things difficult when you want

to input all the data, but you don't know how

much is in the file. We showed you this error so

you would appreciate our new word —EOF. Type:

105 IF EOF(l)

120 GOTO 105

1THEN 130

and RUN . . .EOF checks to see if you've reached

the end of buffer #1 {the number in parentheses).

If you have, EOF(l) equals a-1. If you haven't,

EOF equals 0.

ONE THING AT A TIME

By adding line 105 to the program, the Computer

checks to see if you've reached the End before

inputting the next check. If you have, line 130 clo-

ses communication to the file.

DETAILS...

So far, "CHECKS/DAT" has been easy to handle,

but not very useful. You would probably like to

add more details:

CHECKS

PAYABLE TO AMOUNT EXPENSE

DR. HORN 45.78 MEDICAL

SAFEWAY 22.50 FOOD

FIRST CHRISTIAN 20.00 CONTRIB.

OFFICE SUPPLY 13.67 BUSINESS

Change lines 25 and 115, and add some lines by

typing:

25 WRITE ttl t^5. 78

27 WRITE #1 t"MEDICAL"

110 INPUT #1 tft$i B» Ct

115 PRINT At tB>Ct

LIST the program. This is the way it should look

now:

#1 >"CHECKS/DAT"

"DR. HORN"

#1 ."CHECKS/DAT 1

=-1 THEN 130

10 OPEN "0" t

20 WRITE *1 >

25 WRITE «1 ,a5. 78

27 WRITE «1 t"MEDICAL"

30 CLOSE «1

100 OPEN "I" »

105 IF E0F(1)

110 INPUT #1 ,A$i Bt C$

115 PRINT A$ >Bi Ct

120 GOTO 105

130 CLOSE *1

Now RUN it.

AGOOD TIGHT PROGRAM

What if you need to store awhole list of checks?

Continue to plod along with this program, and it'll

soon be unbearable.

Here, we have atight program which asks you to

INPUT all your data, stores it on disk, and reads

it back into memory. Erase memory and type:

5CLS

10 OPEN "O" **1 i"CHECKS/DAT"

20 INPUT "CHECK PAYABLE TO :"i A$

30 IF At ="" THEN 80

40 INPUT "AMOUNT :*"! B

50 INPUT "EXPENSE :" iC$

GO WRITE «li At tBtC$

70 GOTO 20

80 CLOSE *1

80 CLS

100 PRINT "YOUR CHECKS ARE STORED ON DISK"

110 INPUT "PRESS <ENTER> TO READ THEM"! At

120 OPEN "I" talt "CHECKS/DAT"

130 IF E0F( 1)=-1 THEN 170

140 INPUT *li At iBt Ct

150 PRINT a$; b; Ct

1G0 GOTO 130

170 CLOSE »1

RUN it. Input any checks. When you want to quit,

simply press (ENTER)in answer to the check pay-

able to :prompt. For example:

(ENTER)

CHECK PAYABLE TO :? GOODY BANK (INTER)

AMOUNT :$? 230.97

EXPENSE

CHECK

CAR (ENTER)

PAYABLE TO :? (ENTER)

YOUR CHECKS ARE STORED ON DISK

PRESS (ENTER) TO READ THEM? (ENTER)

GOODY BANK 230.87 CAR

PROGRAMMING EXERCISE

#5.1

Write aprogram which will print

only those checks which were for

JAR expenses.

The answers to all the "Programming Exercises"

are in Appendix A.

CHAPTER CHECKPOINT

1. What is a buffer #1?

2. Why must you OPEN adisk Hie?

3. Why must you CLOSE it?

4. What is the difference between afile OPEN

for input and output?

Try saving many different graphics

programs on disk and calling them

from one main program. Sample

Program 7in Appendix C shows

how.

You can quickly store, organize, and

update all your financial information with

adisk system. See Sample Program 1, 2,

and 8in Appendix Cfor program listings.

izr

°°«

'' \^,*

"-,. ;«^

CHANGING IT ALL AROUND

(Updating aSequential Access File)

Everything you put on the disk and take off of it

goes through aspot in memory called abuffer.

When we told you how to put data on tape in Get-

ting Started With Color BASIC, we didn't talk

about these buffers. We didn't need to. There is

only one buffer which communicates with the tape

recorder —buffer #- 1.

With your disk system, you can use up to 15 buff-

ers. This means you can have up to 15 spots in

memory communicating with 15 different disk

files at the same time.

The reason we brought this subject up is that we

want to demonstrate how to change some of the

data in your file. Tb do this, it is very helpful to use

two buffers.

Note: In Chapter 10, we'll demonstrate how to take

advantage of more of these buffers

Type this program:

10 OPEN "0", Mi "ANIMALS/DAT"

20 WRITE «1 i"HORSE"

30 WRITE *1 t"COW"

am CLOSE *1

RUN it. Now, let's assume you want to change

"COW" to "GIRAFFE!' First, you need to read the

data items into memory with an input program.

Erase memory. Type NEW (ENTEffl and then type:

10 OPEN "I" iM, "ANIMALS/DAT"

20 IF E0F(1) =-1 THEM 110

30 INPUT «1 tA$

40 CLS :PRINT @LOG ."DATA ITEH :" A*

109 GOTO 20

112 CLOSE «1

Then you need to add lines which will allow you to

change one of these data items and store the

change in the disk file. Type:

50 PRINT @451 t"PRESS <ENTER> IF NO

CHANGE" ;

G0 PRINT %2G3, "CHANGE :"!

70 INPUT X%

CHANGING IT ALL AROUND

SO IF X* ="" THEN X$ =

90 WRITE *1 iX*

RUN the program. As soon as the Computer gets

to line 90, it prints:

?FM ERROR IN 90

LIST the program. Line 10 opens buffer #1 to

input data. Line 90, however, is attempting to out-

put data to buffer #1. The Computer won't output

data to abuffer opened for input.

This is where the additional buffer becomes

handy. To output your changed data to the disk,

you can open another buffer for output. Add these

lines:

15 OPEN "0" .*2, "NEW/DAT"

90 WRITE »2* X*

120 CLOSE »2

RUN the program. Change "COW" to "GIRAFFE"

This is the way the entire program looks:

10 OPEN "I". «1 ."ANIMALS/DAT"

15 OPEN "0" .«2. "NEW/DAT"

20 IF EOFt 1) =-1 THEN 110

30 INPUT 81 ,A*

40 CLS :PRINT @10E, "DATA ITEM :" A$

50 PRINT @451. "PRESS <ENTER> IF NO

CHANGE" ;

S0 PRINT @2G3» "CHANGE :"i

70 INPUT X*

B0 IF X$ ="" THEN X* =A*

90 WRITE 82. K$

100 GOTO 20

110 CLOSE »1

120 CLOSE *2

Line 10 OPENs communication to buffer #1 for

input from adisk file named "ANIMALS/DAT."

Line 15 OPENs communication to buffer #2 for

output to adisk file named "NEW/DAT:7

Line 30 inputs A$ from buffer #1. Line 70 allows

you to INPUT X|, which will replace A$. If you

input X$, line 90 outputs it. Line 90 outputs X$ to

buffer #2, which, in turn, WRITEs it to "NEW/

DAT!'

Line 110 CLOSEs communication to buffer #1

and line 120 CLOSEs communication to #2.

Now you have two files. "ANIMALS/DAT" con-

tains the old data and "NEW/DAT" contains the

new. Add these lines to the program and RUN it:

130 KILL "ANIMALS/DAT"

140 RENAME "NEW/DAT" TO "ANIMALS/DAT"

Now the old "ANIMALS/DAT" file is deleted from

the disk and the "NEW/DAT" file has been

renamed to "ANIMALS/DAT." To see what this

updated file contains, SAVE this program if you

want, erase memory, and type and RUN:

10 OPEN "I") 81 ,"ANIMALS/DAT"

20 IF E0F(1) =-1 THEN B0

30 INPUT 81 ,A$

40 PRINT A*

50 GOTO 20

G0 CLOSE «1

Understand? Try these exercises:

PROGRAMMING EXERCISE #0.1

Write aprogram which will allow

you to add animals to "ANIMALS/

DAT'

Hint —You must add them to the

end of the file.

PROGRAMMING EXERCISE #6.2

Write aprogram which will allow

you to delete animals from "ANI-

MALS/DATT'

Ready for the big time? Our next exercise is apro-

gram many of you will want —amailing list pro-

gram. We'll start you out with these lines which

input the names, addresses, and phone numbers of

your club members:

CHANGING IT ALL AOUND

BO OPEN "0". »lf "MEMBERS/DAT"

90 GOSUB 430

100 IF N*="" THEM CL0SE«1:END

110 WRITE *1 iN$t A*. P*

120 GOTO 90

430 CLS: PRINT "PRESS <ENTER> WHEN

FINISHED" :PRINT

440 INPUT "NAME OF MEMBER: "iN$

450 IF N$ ="" THEN 480

4G0 INPUT "ADDRESS :"?A*

470 INPUT "PHONE NUMBER :"! P$

480 RETURN

Now finish it by solving this Programming Exer-

cise. It'll be difficult, but we think you can do it.

Remember, no one's watching. If you get bogged

down, refer to the answer in Appendix Afor help.

PROGRAMMING EXERCISE #6.3

Write aprogram in which you can:

1. See the names, addresses, and

phone numbers ofyour club's

members.

2. Change the addresses ofsome of

the members.

3. Add new members.

4. Delete some of the members.

All of this works quite well on asmall scale, but

how would it work in alarge file? What if you had

500 members in your "MEMBERS/DAT" file and

you wanted to change only the address of the

453rd member?

The process would still be the same. You would

have to input each of the 500 members from one

file and then output them all to another file. All of

this just to change one record. There must be an

easier way!

The easier way is called the direct access method

of programming. It makes your files easier and

faster to update, but in many cases it will make

them take up more space in your disk. The choice

is yours. We'll talk about direct access in the next

chapter.

Note: We've demonstrated short example programs.

There are many ways you could improve them. See

the "Sample Programs" in Appendix Cfor ideas.

CHAPTER CHECKPOINT

Why can 't you input and output data to the

same buffer at the same time?

Can you input data from afile OPENed for

"O"— output?

DISK FILE

STORAGE AftEA

Mo MxwTMice u>mwor HumeeR

AMORE DIRECT APPROACH

(Direct Access to aFile)

Up to now, we haven't been concerned with how

your data is stored on the disk. For example, you

might have put this in a disk file:

"MARIE ALEXANDER*" "J* DO

E»""MARK JONES*" "BILL S

h/DAT it

MITH

'jtout o£>

KMME5/DAT **

What if you want to change "J. DOE," to

"ELLIOTT HOBBS"? You could not ask the Com-

puter to go directly to "J. DOE" The Computer

does not know where it is.

All the files we've created so far have been

"sequential access!' To find aparticular item in a

sequential access file, the Computer must start at

the beginning and search through each item. It

can't go directly to the item. In short, asequential

access file does not take full advantage of your

disk's "filing system."

USING THE DISK FILING SYSTEM

In Chapter 2we talked about how formatting your

disk creates this filing system. In our analogy, the

file cabinets are the disk "tracks" and the file

drawers are the disk "sectors!' You can use tracks

and sectors to immediately find any item you

want.

To do this, you can divide your file into something

which we call "records." You can then write a pro-

gram which stores each record in a sector and

allows you to put data in the records. The next

page shows how your new disk file will look:

AMORE DIRECT APPROAC H

"MARIE ALEXANDER"

record 1

"J.DOE"

record 2

"MARK JONES"

record 3

"BILL SMITH"

record 4

With each record the same length (the length of a

sector), the Computer can go directly to "J. DOE!'

All it has to do is count down to the second record.

We call this a"direct access" file. By direct access,

we mean you can directly access any record you

want in the file.

Adirect access file has one shortcoming. Each

record is the size of asector —256 bytes. Since one

of these bytes holds one character of data, each

record is large enough to hold 256 characters.

This means that our drawing above is alittle mis-

leading. If we illustrated all the empty space in

each record, they would each have to be nearly ten

times as long. We simply don't have enough room

on the page.

If you're abeginner, all this empty space probably

won't bother you. An empty disk can hold up to

612 records —each 256 bytes long. Later on, when

you become more comfortable with programming,

you'll probably want to pack more records into a

disk file. You can then progress to Chapter 9,

where we will demonstrate how to make smaller

records.

PUTTING ARECORD ON DISK

Enough theory! Let's put one record in adisk file.

Since it'll beadirect access file, we don't have to

start with the first. We'll start with the second.

Erase memory and type:

10 OPEN "D" ttil, "NAMES/DAT"

20 WRITE *1 t"J. DOE"

30 PUT *1 .2

40 CLOSE *1

The program looks familiar ...except for the word

PUT in line 30 and the "D" in line 10. More on that

later . .

Now let's add some lines so the Computer will

read this record back into its main memory. Type:

34 GET 81 t2

3G INPUT #1 ,A*

38 PRINT A$

Note that line 34 uses another new word —GET

Hmmm ...any ideas? Let's look at the entire

program:

10 OPEN "D"i »1

"NAMES/DAT"

2(3 WRITE »1 ,"J. DOE"

30 PUT *1 .2

3 a GET «1 i2

36 INPUT »1 pA$

38 PRINT A$

40 CLOSE *1

RUN it . . . You'll hear the now familiar sound from

your disk drive. The Computer is writing "J.

DOE" in the disk file and then reading it back into

memory. Here's how ..

Line 10 OPENs buffer #1 which will communi-

cate with adisk file named "NAMES/DAT." As we

said in the last two chapters, buffer #1 is one of

the 15 "buffer" areas which can communicate with

your disk.

Communication is being OPENed for "D." "D"

stands for direct access. Unlike sequential access,

you don't have to specify whether you're OPENing

AMORe DIRECT APPROACH

communication for output or input. The "D" suf-

fices for both.

Line 20 WRITEs "J. DOE" to buffer #1. Since this

program is open for direct access, "J. DOE" will

remain in buffer #1 until the program sends it

elsewhere.

Line 30 does just that. It PUTs the contents of

buffer #1 into the disk file as record 2:

Notice our drawing shows only two records in the

file. GET record 4. Type:

34 GET »1 .a

and RUN ...The Computer gives you an IE (Input

past the End of the File) error. This is because the

last record the program PUT in the file was record

number 2. Hence, record 2became the end of the

file.

Note: Didn't get this error? You must already have

"NAMES/DAT" file on your disk with three or mo.

records.

record 1

"JDOE"

record 2/

W^MES/DAT" ^

To PUT more records in the file, add these lines.

Then RUN the program:

31 WRITE »1 t"BILL SMITH"

32 PUT si ,a

Now your "NAMES/DAT" file will have these four

records:

At this point, "J. DOE" is no longer in buffer #1.

It is in record 2of the disk file.

Line 34 GETs record 2and reads it back into

buffer #1. Now "J. DOE" is in both the disk file

and buffer #1.

Line 36 INPUTs the record from buffer #1 into

main memory and labels it A$. Now "J. DOE" is

in both the disk file and main memory. It is no

longer in buffer #1.

With "J. DOE" in main memory, line 38 can

PRINT it.

record 1

"J.DOE" .

record 2

record 3

"BILL SMITH"

record 4

Note: In the sequential access programs in Chapters

5and 6, you didn't need PUT and GET. The Com-

puter did this automatically. The OPEN line specified

whether the buffer should output (PUT) data into the

disk file or input (GET) data from the disk file.

JtMdb

XW/)M£S

5/DA7 >*

AMORE DIRECT APPROACH

PROGRAMMING EXERCISE 7.1

Change lines 32 and 34 so that your

Computer will use record 3 to PUT

and GET "BILL SMITH."

itV-,

:*W ;*&*&&* ,1 -

DEALING WITH GARBAGE

You have not yet PUT anything in record 1.Ask

the Computer to GET record 1and see what hap-

pens. Type this and RUN:

34 GET »1 >1

Since the Computer didn't PUT anything in

record 1, record 1contains whatever "garbage" is

already there.

When you ask the Computer to GET and INPUT

it, it will either get the "garbage" or give you an

OS (Out of String Space) error. The OS error sim-

ply means the garbage consumes more than 200

bytes (characters).

Since your empty records will contain garbage

until you fill them with something, it's agood idea

to put some kind of data in all of them in advance.

Erase memory and type this program:

10 OPEN "D" t*1 i"NAMES/DAT"

20 FOR ;; =1TO 10

30 WRITE *1 ."NO NAME"

40 PUT »l ,X

50 NEXT X

G0 CLOSE «1

RUN it. This program sets up adisk file named

"NAMES/DAT" which has ten records. Each

record contains "NO NAME":

KMtie$fD#r"

"NO NAME "

record 1

"NO NAME"

record 2

"NO NAME"

record 3

"NO NAME"

record 4

"NO NAME"

record 5

"NO NAME"

record 6

"NO NAME"

record 7

"NO NAME"

record 8

"NO NAME"

record 9

"NO NAME"

record 10

juhjL

xWfiM5S/D#T"

Now erase memory and type this:

10 OPEN "D" i#1 >"NAMES/DAT"

20 INPUT "RECORD NO. (1-10) "i R

30 IF R>10 THEN 20

40 IF R<1THEN 130

50 GET «1 .R

G0 INPUT «1 .A$

70 PRINT A$ "-- IS THE NAME IN RECORD" R

AMORE OIRECT APPROACH

90 INPUT "TYPE NEW NAME ELSE PRESS

<ENTER>"; At

90 if fi* ="" THEN 20

100 WRITE »1 ,A*

110 PUT *1 tR

120 GOTO 20

130 CLOSE *1

RUN it. See how all your records initially contain

"NO NAME." Then, you can change the data in

any of the records at will, as many times as you

want. (To end the program, type aas the

RECORD NO.)

READING ALL THE RECORDS

At this point, you might like the Computer to

print all of the records in your "NAMES/DAT" file

with their appropriate record numbers. SAVE

your program, if you want, erase memory, type,

and RUN:

10 OPEN "D" ,*1 »"NAMES/DAT"

20 R=1

32 GET *1 .R

40 INPUT «1 tAt

50 PRINT At "

60 IF R=10 THEN 90

70 R=R+1

80 GOTO 30

90 CLOSE *1

13 IN RECORD" R

Line 20 makes Requal to 1. In the next lines, the

Computer GETs, INPUTs, and PRINTs record 1.

Line 70 then makes Requal to 2and the whole

process is repeated with record 2. When Requals

10 —the last record in the file —the program ends.

There are many occasions when you will not know

the last record number in the file. Change line 60

and RUN the program:

G0 IF RL0F( 1)THEN 90

LOF looks at the file which buffer #1 (the number

in parenthesis) is communicating with. It tells

the Computer what the last record number in that

file is.

MORE POWER TO A RECORD

So far, we have been PUTting only one "field" of

data in each record. We can make the file more

organized by subdividing each record into several

fields.

Erase memory, type, and RUN this program:

*1 ."BUG9/DAT"

"FLIE9" t1000000* "HAIRY"

10 OPEN "D"

20 WRITE *1

30 PUT »1 .2

34 GET #1 .2

35 INPUT *i .D*. N. T$

38 PRINT Dt ,Nt Tt

WCLOSE #1

Line 20 WRITEs three fields of data into buffer

#1. Then, line 30 PUTs the entire contents of

buffer #1 (all three fields) into record 2of the file:

*BU&S/DfilT

record 1

"FLIES tI000000 »"HAIRY"

record 2/

Line 34 GETs everything in record 2and reads it

into buffer #1. Then, line 36 INPUTs all three

fields of data from buffer #1 and labels them as

D$, N, and T$.

Try substituting this for line 36 and RUN . .

38 INPUT *1 iDt

Since this line asks the Computer to INPUT only

the first field of data in buffer #1, it INPUTs only

"FLIES."

A MORE DIP.ECT APPP.OACH

PROGRAMMING EXERCISE 7.2

What do you think the Computer

would print if you ran the pro-

gram, using this for line 36? Why?

3G INPUT «1. N

PROGRAMMING EXERCISE 7.3

CHAPTER CHECKPOINT

1. What are records? Why must you use them

to access data directly?

2. What are Gelds?

3. Whatis the difference between asequential

access and adirect access file?

4. Why is it quicker to update adirect access

Hie?

Change the program which stores

the "NAMES/DAT" file so that

each record will contain five fields

of data:

1. name

2. address

3. city

4. state

5. zip

SECTION III

TOIE IBEIFMIEID) ©nSDS IPMDOISAKfl

After writing disk programs for awhile, you might

want to make them more efficient. Perhaps you'll

want to put more data on the disk. You might also

want to economize on memory space or use some

extra buffer space.

At that time, we invite all of you ambitious people

to read this section. The subject matter is more

advanced and technical. Once you finish it, though,

you'll have all the information you need to write the

best possible disk programs.

HOW MUCH CAN ONE DISK HOLD?

(What the Computer writes in aDisk File)

Your disk is divided into thousands of equal-sized

units. Each unit is a"byte." One of these bytes can

hold one character. Thus, the word STRAW will

consume five bytes of disk space.

An empty disk contains 161,280 bytes. 4,608 of

them house the directory. This leaves you 156,672

for your disk files.

Note: Adisk contains 35 tracks. Each track contains

18 256-byte sectors, or 18x256 =4,608 bytes. One of

the tracks is for the directory. This leaves 156,672

bytes (4,608 bytes per track x34 tracks).

Does this mean you can use the entire 156,672

bytes for data? Possibly. There are two factors

which will determine this.

The first has to do with the way the Computer

allocates space for adisk file. It stores afile in clus-

ters. (We call them granules.) Each granule con-

tains 2,304 bytes.

Because of this, all of your disk files will contain

amultiple of 2,304 bytes. If your file contains

2,305 bytes of data, for example, the Computer

will allocate 2granules for it, or 4,608 bytes (2,304

x2).

The Computer allocates file space in this manner

because it's the most efficient way to create afile.

It is very tricky to change this and is something

that only very technical people would want to do.

(See Chapter 11, Technical Information, for addi-

tional information.)

The second factor which affects how much data

you can put in adisk file is your program. Some

disk programs are very efficient. Others put alot

of overhead and empty space in the file.

In the next two chapters, we're going to compare

eight different types of programs. Each will store

the same data —5, 'TEN;' -16, and "PAPER" —

in adisk file named "OFFICE/DAT." The amount

of overhead and empty space each program will

put in "OFFICE/DAT" will vary greatly.

HOW MUCH CAN ONE DISK HOLD?

WRITING ON THE DISK

Program 1uses WRITE to put this data on the

disk. Type and RUN it:

PROGRAM 1

21 bytes

10 OPEN "0% «lf "OFFICE/DAT"

20 WRITE *1 ,5, "PEN"

30 WRITE «1 i-16 »"PAPER"

40 CLOSE #1

There is an easy way to see what lines 20 and 30

wrote on your disk. Type these two lines exactly as

they are above, but leave off the #1 in each line.

This will prevent the Computer from writing the

data on your disk (via buffer #1). The Computer

will write it on your screen instead. Type:

WRITE 5, "PEN" (ENTER)

WRITE -IS, "PAPER" (HDIE)

Look very carefully at what the Computer

WRITEs. Every blank space and punctuation

mark counts.

Notice the way the Computer WRITEs the two

strings (PEN and PAPER). It puts quotation

marks around them. It WRITEs the numbers (5

and -16) differently. If the number's negative, the

Computer puts aminus sign in front of it. If it's

positive, the Computer simply puts a blank space

in front of it.

There are two characters you typed which the

Computer didn't WRITE on the screen. These are

the two (ENTER) characters which you typed at the

end of the WRITE lines. It skipped down to the

next line instead:

"PEN'

-IS, "PAPER"

When writing on the disk, the Computer actually

WRITEs each (ENTER) character exactly as you

typed it. This illustration shows what Program 1

WRITEs on your disk. (We used asterisks to rep-

resent the [ENTER) characters):

fi<*/dat»

5t"PE N "*-16i"PAPER"*

Note: Want to be precise? What the Computer

actually WRITEs on the disk are binary codex. Each

character has an ASCII code (see Appendix D) which

the Computer converts to abinary number.

Count the characters. Make each (ENTER) (repre-

sented by an asterisk), comma, and quotation

mark count for one character each. Don't forget

the blank space preceding 5. What you should

come up with is 21 characters. Program 1puts 21

bytes in "OFFICE/DAT."

Since the Computer allocates file space in clusters,

"OFFICE/DAT" will actually consume 1granule

of disk space or 2,304 bytes. However, for the pur-

pose of comparison, we'll only look at the 21 bytes

which Program 1puts in "OFFICE/DAT:'

ADISK-EYE VIEW

To input "OFFICE/DAT," type and RUN this

"INPUT Program" (erase memory first):

INPUT PROGRAM

10 CLS

20 OPEN "I", #1» "OFFICE/DAT"

30 IF E0F< 1)=-1 THEN 80

40 INPUT #1 ,A, Bt

50 PRINT: PRINT "DATA ITEM :" A

60 PRINT "DATA ITEM :"B$

70 GOTO 30

B0 CLOSE *l

It did input your data items. However, it did not

input the quotation marks, commas, and blank

spaces which we told you were interspersed with

your data.

To actually see what Program 1wrote on your

disk, you can use a"LINE INPUT Program." First

HOW MUCH CAN ONE DISK HOLD?

SAVE the "INPUT Program" you now have in

memory. (You'll be using it later.)

Now change it into a"LINE INPUT Program."

Delete line 50 and change lines 40 and 60. Type:

40 LINE INPUT #1 ,L*

G0 PRINT "DATA LINE :" L*

and RUN ...Line 40 INPUTs an entire LINE,

rather than one single data item from the disk file.

This LINE includes everything up to the (ENTER)

character —punctuation marks, spaces and all.

In the "OFFICE/DAT" file, the first LINE contains

5, "PEN." Line 40 labels this line as L$ and line 60

PRINTs it on your screen.

The program then INPUTs and PRINTs -16,

"PAPER" —the second and final line in the file.

We can easily alter this program so that it will

count how many bytes are in the file. Add these

lines and RUN it:

25 PRINT "THIS FILE CONTAINS :"

27 PRINT: PRINT: PRINT: PRINT

57 m=Lt+ "*"

G0 PRINT Mt!

G5 L=LEN(Mt) +L

90 PRINT @394t L"BYTES"

Line 57 adds an asterisk to each LINE. This aster-

isk represents the (ENTER) character. Line 65 then

counts the total number of characters (bytes) in

each line.

This is the entire "LINE INPUT Program":

PLINE INPUT PROGRAM

10 CLS

20 OPEN "I"* «li "OFFICE/DAT"

25 PRINT "THIS FILE CONTAINS ;

27 PRINT: PRINT: PRINT: PRINT

30 IF EOFU) =-1 THEN 80

40 LINE INPUT *1 fL*

57 M* =L* +"*"

G0 PRINT M$!

G5 L=LEN(M$) +L

70 GOTO 30

B0 CLOSE *l

90 PRINT @394 >L"BYTES'

SAVE it. It will be useful in comparing what Pro-

grams 2, 3, and 4put in your disk file.

PRINT—FOR A CHANGE

So far, we've used only WRITE to put data in a

disk file. If you've used other forms of BASIC, you

might be accustomed to using PRINT rather than

WRITE.

The Color Computer disk system allows you to do

this. However, PRINT is much more tricky to use.

If you're not used to it, don't bother learning all

this. Skip to Program 4.

...Still with us? KILL your old "OFFICE/DAT"

file by typing:

KILL "OFFICE/DAT" (ENTER)

Now erase memory, and type and run Program 2.

Then RUN the INPUT or the LINE INPUT Pro-

gram, if you'd like.

Here's Program 2:

PROGRAM 2

42 bytes

10 OPEN "0" ,*1 ,"OFFICE/DAT"

20 PRINT 81 ,5» "PEN"

30 PRINT *1 ,-1G »"PAPER"

40 CLOSE »1

Lines 20 and 30 PRINT your data to buffer #1

which, as you know, is one of the 15 buffers which

will send your data to the disk file. To see what

Program 2PRINTs, type:

PRINT 5» "PEN" (ENTER)

PRINT -1G "PAPER" [ENTER)

Notice the Computer did not enclose the strings

—PEN and PAPER —in quotes, as WRITE did.

This will be important to know later.

Now look at the blank spaces. We'll start with the

first one —the one before the 5. This means the

HOW MUCH CAN ONE DISK HOLD?

same thing it did with WRITE. 5is apositive

number.

Now for the other blank spaces ... Whenever the

Computer PRINTs anumber, it PRINTs one

"trailing" blank space after it. This explains the

first blank space after the 5 and -16.

How about all the additional spaces? Remember,

from Getting Started With Color BASIC, what a

comma in the PRINT line does? It causes the Com-

puter to PRINT your data in columns, inserting

spaces between the columns.

The Computer will PRINT every single one of

these blank spaces in your disk file:

Cn{L>

*OFFICE/DAT'

PEN*- IB

PAPER*^.

JtMxL *g "OFFICE/DAT "

Count all the characters. Program 2puts 42 bytes

into "OFFICE/DAT."

Note: Unclear about what commas do in aPRINT

line? Type some more PRINT lines with commas

between data items:

PRINT 1. 2, 3* H, 5, 6> 1, BHHTEffi

PRINT 'HORSE 11

,"COW'f ''RABBIT", "OOG

PRINTING LESS

You might feel that all the blank spaces PRINT

inserts in your disk file are awaste of space. They

are. The way to get around this waste is to use

semi-colons. You might again recall, from Getting

Started With Color BASIC, that semi-colons in a

PRINT line compress your data. Type:

"OFFICE/DAT" file. Then type and RUN this

program:

PROGRAM 3

17 bytes

10 OPEN "0" .*1 ,"OFFICE

20 PRINT #1 .5i "PEN"

30 PRINT *1 r-lGi "PflPEf?

40 CLOSE *1

This is what Program 3PRINTs on your disk. (Use

the LINE INPUT Program to test this, if you'd

like):

*0FFIC£/P*T \

5PEN*-1G PAPER*

Very efficient. Only 17 bytes. There are only three

blank spaces in this disk file. There is aspace

before the 5(to indicate that it is positive) and

spaces after 5and -16 (to indicate that they are

numbers). There are no blank spaces around the

strings.

PRINT 5! "PEN" (ENTER]

PRINT -lGi "PAPER" (EHTEB)

You can compress your data on the disk in the

same manner. Erase memory and KILL your old

THE TRICKY PART

There are certain types of PRINT lines which are

tricky. (We did warn you, didn't we?) Type:

HOW MUCH CAN ONE DISK HOLD?

PRINT "PEN"! "PAPER" fEHTER)

PRINT "JONES. MARY" (iNTEff)

print "pen". 5(mm

The line PRINT «l >"PEN" i"PAPER" (in your disk

program) would print this in your disk file:

PENPAPER*

The Computer would read PEN 5

(with all the blank spaces) back into memory as

one item. (Reason; although the Computer nor-

mally interprets blank spaces as adelimeter, it will

not interpret them in this way when they follow a

string and precede anumber).

For more information on using PRINT in disk pro-

grams, see the TRS-80 Model I, Model II, or Model

III Disk System Owner's Manual.

AN ATTRACTIVE DISK FILE

The Computer would read PENPAPER back into

memory as one item. (Reason: there is not a"deli-

meter" —acomma, quotation mark, or space —to

separate PEN from PAPER).

The line PRINT *l ,"JONES >MARY" would print

this in your disk file:

JONES tMARY*

The Computer would read JONES, MARY back

as two items: JONES and MARY. (Reason: The

Computer interprets the comma as a delimeter).

The line PRINT «i ,"PEN" ,5, would print this

in your disk file:

PRINT USING is another word you can substitute

for WRITE. We discussed PRINT USING in Going

Ahead With Extended Color BASIC). Type:

PRINT USING "1

(ENTER)

PRINT USING "I

'ENTER)

*,$+#«.**" 5"PEN" <5

!$+»#,»»" !"PAPER" ,-16

You can get the Computer to print these same

images on your disk with this program. KILL

"OFFICE/DAT," erase memory, and type and

RUN:

PROGRAM 4

32 bytes

10 OPEN "0" t#1 t"OFFICE/DAT"

20 PRINT #1. USING "X **+##,«#"!

"PEN" f5

30 PRINT tl, USING "X 2$+*» (#t"i

"PAPER"* -IB

40 CLOSE #1

PEN

which prints this in your disk file:

PEN $+ 5.00*PAPER

*-1B.130*

HOW MUCH CAN ONE DISK HOLD?

Note: There are five blank spaces between the %char-

acters in lines 20 and 30. Counting the two %char-

acters, this string field (for printing PEN and

PAPER) contains seven bytes.

Now the data is already in an attractive print for-

mat. You can input and print it using asimple line

input program. Erase memory, type and RUN:

more programs which will put the same data in

direct access files.

CHAPTER CHECKPOINT

sen INPUT and

IINT line cause

iaPRINT tine

IINT strings?

10 OPEN "I" >*1 >

20 IF EOFtl) =-1

30 LINE INPUT »1 *

40 PRINT At

50 GOTO 20

G0 CLOSE *1

1. What is the minimum size of adisk Sle?

Why can 't it be smaller?

9. Hnvr rfnan th* Cnmngter WJRJtTFf ntimhe

OFFICE/DAT"

"'""

THEN G0

All of the files we've created in this chapter are

sequential access. The next chapter compares four

m^diMjftlef}

3. How does it WRITE strings

4. What is the' difference betwi

LINE INPUT?

5. What does a comma in aPI

the Computer to do?

6. What does asemi-colon it

cause it to do?

7. How does the Computer PE

f"l

TRIMMING THE FAT OUT OF DIRECT ACCESS

(Formatting aDirect Access File)

/» Direct access files often contain alot of empty

space. For example, our first program is very sim-

ilar to Program 1from the last chapter. The

WRITE lines are identical. However, because it is

direct access, it will put 512 bytes in "OFFICE/

DAT":

PROGRAM 5

512 bytes

10 OPEN "D"

20 WRITE #1 t

30 PUT «1 ,1

40 WRITE «1 ,

50 PUT *1 i2

60 CLOSE «1

•It "OFFICE/DAT'

5» "PEN"

-16» "PAPER"

Adirect access program puts your data inside rec-

ords. Each record is 256 bytes. Program 5puts two

records in the "OFFICE/DAT" file. Therefore, it

will consume 2x256, or 512 bytes:

IfiliiiiililiilllUiiii!

miimiiiiiiiflimim

HBiiiiiiiimmiinii

miifiiiiiHHHim

miiiiiiiiiiii11111111

BIIBilllllillllieiiiilll

iiiiiiliiiiiiiiiiaiii i i

Bisiiiiaiiiiiiinigiim

iiniaagiiiBBaBBiaeiiiii

TRIMMING THE FAT OUT OF OIRECT ACCESS

record 1

IB PAPER"*

record 2

*o?Fice/mT"

This obviously wastes amassive amount of space.

Notice that what the Computer actually writes in

each record:

5, "PEN"*

-IB, "PAPER"*

is the same as what Program 1wrote. Count the

bytes. That's nine bytes in the first record and 12

in the second. You'll need to know this for our next

program.

Note: We could have used PRINT or PRINT USING

rather than WRITE, The Computer would have then

PRINTed your data inside each record using the

PRINT or PRINT USING format.

TRIMMING THE FAT

Program 6is the same as Program 5, except that

we inserted anumber 12 at the end of line 10, This

tells the Computer to make each record 12 bytes

long:

PROGRAM 6

24 bytes

10 OPEN "B"i «lt "OFFICE/DAT". 12

20 WRITE »1 t5,"PEN"

30 PUT »1 .I

40 WRITE *1 ,-IB. "PAPER"

50 PUT «1 t2

B0 CLOSE *1

and really whittles this file down:

/"OFFICE/DAT"

5,"pE N "*

record 1

1G*"PAPE R "*

record 2

"0FFIC£/DAT"

In adirect access file, all records must be the same

length. {We explained why in Chapter 7.) If you

don't tell the Computer how long to make them,

they will all be 256 bytes.

In this program, we made each record 12 bytes, the

size of the largest record. Type and RUN Program

6, if you'd like, (Be sure to erase memory and

KILL your old "OFFICE/DAT" file first.) After

RUNning Program 6you can use this program to

input the file:

TRIMMING THE FAT OUT OF DIRECT ACCESS

DIRECT INPUT PROGRAM

*1 'OFFICE/DAT

10 OPEN "D".

20 R=R+1

30 GET #1 ,R

38 INPUT Hi A, B$

50 PRINT "RECORD" R":" A

G0 IF LOF(l) <> RTHEN 20

70 CLOSE »1

Note: You can't use the "LINE INPUT Program" to

determine how many bytes this file consumes. LINE

INPUT does not input the spaces in arecord which

follow the ;ENTER) character.

EFFICIENCY, EFFICIENCY . .

We can get even more efficient. Our next direct

access program consumes only 16 bytes. Erase

memory, KILL the old "OFFICE/DAT" file, and

type and RUN Program 7.

PROGRAM 7

16 bytes

10 OPEN "D"» *1 ."OFFICE/DAT" i8

20 FIELD »1

3AS At t5AS Bt

30 LSET At ="5"

40 LSET 8$ ="PEN"

50 PUT »1 .1

S0 LSET A$ ="-IS"

70 LSET B$ ="PAPER"

90 PUT «1 .2

90 CLOSE *1

There are two new words in this program which

we'll talk about later. Let's see what the program

does first. SAVE it. Then erase memory and input

the file with this program:

FIELDED INPUT PROGRAM

10 OPEN "D" ,•1t'OFFICE/DAT" .S

20 FIELD *i ,3AS A* >5AS B*

30 R=R+1

mGET »1 ,R

50 PRINT "RECORD" R":" At! Bt

60 IF LOF(l) <> RTHEN 30

70 CLOSE »1

By using FIELD and LSET, your program will

work the same as any direct access program. The

difference is what FIELD and LSET put in each

record:

PEN

record 1

-16PAPE R

record 2

"OFF/CS/OAT

Only the bare essentials. Here's how Program 7

works ..

Line 20 tells the Computer to divide each record

into two fields. The first field is A$ and the second

is B$. These two fields will be the same size in

every record, A$ will always be 3bytes and B$

will always be 5 bytes.

Now that we've established this, we can put data

in each field. Line 30 LSETs 5in the A$ field

(SETs the character 5to the Left of A$). Since the

character 5only consumes 1byte and there are 3

bytes in the A$ field, there are 2empty spaces at

the end of 5.

Notice we had to convert the number 5to astring

by putting quotes around it. You cannot LSET a

number. You must convert it to astring.

Line 40 LSETs the word PEN in the B$ field.

Again, this leaves 2empty spaces at the end of A$,

since PEN is 3bytes.

Line 50 PUTs all this in record 1. Then, the same

process is repeated for record 2.

TRIMMING THE FAT OUT OF DIRECT ACCESS

Now let's look at the "Fielded INPUT Program:'

Notice we used aFIELD line. RUN the program

without line 20 and see what happens ..

Without aFIELD line, the Computer does not

know where the two fields are. Whenever you

input FIELDed records, use aFIELD line in your

input program.

Can you guess what the Computer would do if you

tried to LSET along string, such as "123456789,"

into one of the fields? LOAD Program 7, change

line 30, and RUN the program. (First, SAVE the

"Fielded INPUT Program" with line 20 reinstated.):

30 LSET A* ="lZGaSGTSa"

Now load and RUN the "Fielded INPUT

Program."

A$ is only 3 bytes. Therefore, the Computer only

LSETs the first 3bytes of "123456789." It chops

the remaining characters off:

^OFFICE /OA7"

Mmm

record 1

record 2

"OFF/C&/ DAT

More on this later .. . Before going on to the next

program, try writing your own FIELDed program:

PROGRAMMING EXERCISE

#9.1

Write a direct access program to

put amailing list in adisk Hie.

Make each record 57 bytes with

these six fields:

1. last name—15 bytes

2. first name—10 bytes

3. address —15 bytes

4. city—10 bytes

5. state —2bytes

6. zip code —5bytes

^£3§§§i^

:.\l Vjl ;.« "''.-. :'-

PROGRAMMING EXERCISE

#9.2

Write aprogram to input the file

you created in Exercise #9.1.

ascs-ffira-afi

ANUMBER IS ANUMBER, ..

Let's assume you will be putting alot of numbers

in your disk file. Every number might be adiffer-

ent length:

-5.237632 31 673285

However, it is very important that the Computer

not chop any of the digits off. This might entirely

change the number's value.

The word MKN$ will solve this problem:

PROGRAM 8

20 bytes

10 OPEN "D" t»1 p"OFFICE/DAT"

20 FIELD *l t5AS A* ,5AS Bt

30 LSET ft* =MKNt<5)

40 LSET B* ="PEN"

50 PUT *1 p1

60 LSET At =MKN$t-iG)

70 LSET Bt ="PAPER"

80 PUT *1 >2

90 CLOSE »1

The only difference between this program and pro-

gram 7is lines 10, 20, 30, and 60. This is what it

stores in your disk file:

THIMMING THE FAT OUT OF DIRECT ACCESS

Jfi€JUM*U*Utf' off

/%bFF!C£/DAT"

record 1

SAPER

*office:/dat

Coda, ^&tr/6

MKN$ converts anumber to acoded string.

Regardless of how long the number is, MKN$ will

always convert it to astring that is five bytes long.

For example, change line 30 to LSET anumber

with more than five digits:

30 LSET A$ =MKN$(12345G7B9)

Erase memory, KILL "OFFICE/DAT," and type

and RUN the program. This is what it stores in

your disk file:

^CfcflCE/mT 9

To read this program in, you need to decode the

string. LOAD the "Fielded INPUT Program" and

make these changes to it:

10 OPEN "D" ,#1 ,"OFFICE/DAT" ,10

20 FIELD *i ,5AS A* ,5AS B$

50 PRINT "RECORD" R":";CYN(A$)i B$

and RUN it ...CVN (in line 50) decodes A$ to the

number it represents.

Note: The Computer only sees the first 9digits of a

number. It rounds the rent off.

PROGRAMMING

EXERCISE #0.3

Write afielded direct access pro-

gram which will store the popula-

tions of all the countries. Make

each record contain 15 bytes with

these two fields:

1. country —10 bytes

2. population —5bytes

WBPI^^^H^BOWi^PBBB

--— 5Jswbu

Ofdc j*v /23f56>7&7

"OFFICE/OfiT"

PROGRAMMING

EXERCISE #9.4

Write aprogram which will input

the Hie you created in Exercise

#9.3.

CHAPTER CHECKPOINT

1. Ifyou do not specify the record length, how

many bytes will each record contain?

2. Why must you include aFIELD line when

you LSETyour data?

3. Howmanybytes will MKN$ convert anum-

ber into?

•t %

SHUFFLING DISK FILES

(Merging programs, using many buffers)

Because storing and retrieving disk files is so easy,

you will want to use them as much as you can. In

this chapter, we're going to talk about some spe-

cial ways you can use them.

MERGING PROGRAM FILES

With the first method, you can build aprogram

out of related program "modules" SAVEd on disk.

You can then MERGE any of these program files

with whatever program you have in memory.

Type and SAVE these two related programs:

10 REM AGE CONVERSION TO MONTHS

20 N=N*12

30 A* =STR*(N) +"MONTHS"

SAUE"MONTHS/AGE", A(ENTER)

10 REM AGE CONVERSION TO WEEKS

20 N=N*52

30 A* =STRt(N) +"WEEKS"

Be sure to type the Awhen you SAVE these pro-

grams. We'll explain why later ...Erase memory.

Now put this program in memory:

5INPUT "TYPE YOUR AGE" iN

40 PRINT "YOU HAVE LIVED" A$

and combine it with one of the programs you

SAVEd. Type:

SAVE "WEEKS/AGE", A(ENTER)

MERGE "MONTHS/AGE" (ENTERl

LIST the program ...The Computer has MERGEd

"MONTHS/AGE" with the program you have in

memory. Notice the line numbers are the same as

they were in each individual program.

At this point, this is the program you have in

memory:

5INPUT "TYPE YOUR AGE" iN

10 REM AGE CONVERSION TO MONTHS

20 N=N*12

SHUFFLING DISK FILES

30 A* =STR*(N) +"MONTHS"

40 PRINT "YOU HAVE LIVED ABOUT' A$

MERGE "WEEKS/AGE" with it by typing MERGE

"WEEKS/AGE" (ESTER) .Then LIST the MERGEd

program.

Notice that lines 10, 20, and 30 of the program you

had in memory were replaced by lines 10, 20, and

30 of the "WEEKS/AGE" program.

The line numbers tell the Computer how to merge

the two programs. When there is aconflict of line

numbers (two line 10s) fthe line from the disk file

prevails.

Now we'll get technical (for those of you who are

interested). What the Computer normally writes

in your disk file is the ASCII code for each char-

acter of data. For example, it writes the word AT

with two codes —the ASCII code for "A" (65) and

the ASCII code for *T" (84). (The ASCII codes are

all listed in Appendix D).

However, when it SAVEs aprogram, it writes the

BASIC words differently. To save space, it com-

presses each BASIC word into aone-byte "binary"

code.

You can't MERGE afile which contains these

binary codes. This is why we had you type the A

when you SAVEd the two programs above. The A

tells the Computer to write the ASCII codes for

each BASIC word rather than the binary code.

By checking the directory, you can see if the data

in your files are in ASCII or binary codes. If there

is an "A" in the fourth column, it's all in ASCII

codes. A"B" indicates that some of the words are

in binary codes.

Note: Try typing MERGE "MONTHS/AGE" ,ft ^HTFffi.

The Rtells the Computer to RUN the program after

it's MERGEd.

USING MORE BUFFER SPACE

When you start-up your disk system, it sets aside

two buffer areas in memory for disk communica-

tion. You can use either or both of them for read-

ing or writing data to a disk file.

Up to now, that's all we've used —buffers #1 and

#2. But, as we've said earlier, you can use up to 15

disk buffer areas.

To use more than 2buffers, you must first reserve

space in memory for them. To do this, use the word

FILES. For example, FILES 3reserves 3buffers.

Making use of all these buffers will greatly sim-

plify your programs. For example, let's assume

you own acomputer school. To organize it, you

first put all your students in afile named "COM-

PUTER/SCHr Erase memory, type and RUN:

10 OPEN "0". *1 ."C0NPUTER/SCH"

20 FOR X=1TO B

30 READ At

40 PRINT *1 .A$

50 NEXT X

G0 CLOSE #1

70 DATA JON iSCOTT ,CAROLYN

80 DATA DONNA. BILL rBOB

Now you can write this program to assign the stu-

dents to aBASIC or assembly-language class.

Erase memory and type this "Class Assignment

Program":

ICLASS ASSIGNMENT PROGRAM

»l

»3

10 FILES 3

20 OPEN "0" i

30 OPEN "0" .

WOPEN "I"

50 IF E0F(3)

G0 INPUT «3.

70 PRINT

80 INPUT

LANGUAGE"! R

90 IF R>2THEN 80

100 WRITE 8R tST$

110 GOTO 50

120 CLOSE 81

130 CLOSE 82

140 CLOSE 83

"BA5IC/CLS"

"ASSEMBLY/CLS"

"C0MPUTER/SCH"

1THEN 120

ST4

PRINT ST$

(IS BASIC

RUN it. After assigning all the students to aclass,

you can print a class roster with this program.

Erase memory, type, and RUN:

SHUFFLING DISK FILES

CLASS ROSTER PROGRAM

10 cls

28 PRINT "BASIC/CLS" :PRINT

30 OPEN "I". «1» "BASIC/CLS"

38 IF EOFU) =-1 THEN 80

50 INPUT »1» A*

S0 PRINT A$

70 goto aa

B0 CLOSE »1

Note: Substitute "ASSEMBLY/CLS" for "BASIC/

CLS" in lines 20 and 30 to print the class roster of the

assembly language class.

The "Class Assignment Program" has three buff-

ers open at the same time. Because of this, you are

able to communicate with three disk files at the

same time.

Line 10 reserves memory for these three buffers.

Lines 20-40 OPENs the three buffers. Then, line

60 INPUTs astudent from "COMPUTER/SCH"

into buffer #3.

Line 100 WRITEs the name of the student to

either buffer #1 ("BASIC/CLS") or buffer #2

("ASSEMBLY/CLS").

When all the students from buffer #3 ("STU-

DENT/SCH") have been input, line 50 sends the

Computer to lines 120-140, which CLOSEs the

three buffers.

CROWDING THE BUFFER

There's one more thing you'll like about FILES.

Erase memory, type, and RUN:

10 CLEAR £100

20 files 1,am

30 A$ ="NORMALLY tYOU WILL NOT BE ABLE TO

PUT ALL OF THESE SENTENCES IN ADISK

FILE AT THE SAME TIME. "

£10 B$ ="THIS IS BECAUSE, WITHOUT USING

FILES, YOU WILL ONLY HAVE ATOTAL OF

25G BYTES OF BUFFER SPACE. "

50 C$ ="IN THIS PROGRAM* WE'VE RESERVED

£100 BYTES OF BUFFER SPACE, "

E0 D$ ="THIS WAY YOU CAN SEND ALL OF

THESE SENTENCES TO THE BUFFER AT THE

SAME TIME. "

70 E* ="WHICH WILL OUTPUT THEM ALL TO THE

DISK FILE AT ONCE, "

80 OPEN "0" ,»1 ,"WORD/DAT"

90 WRITE #1 .A*. B$ ,C$ ,Dt ,Et

100 CLOSE #1

Want to input this paragraph? Add these lines and

RUN:

200 OPEN "I" ,#1 ,"WORD/DAT"

210 INPUT #1 ,At, Bt, Ct, Dt tE$

220 CLS

230 PRINT At; Bt; Cti Dt !E$

240 CLOSE #1

Note: You can make the buffer as targe as you want

CHAPTER CHECKPOINT

Howmustyou SAVE aprogram which yo,

wUl want to MERGE?

When the two programs you're mergin

both have the same line numbers, whic.

lines prevail?

How many buffers does the Compute

reserve when it starts-up?

How much hunter space does it reserve?

What does FILES 3, 3000 mean?

HtvttT^Ci^ ^<5^

"PR^ck

•:

:-.

TECHNICAL INFORMATION

(Machine-Language Input/Output)

In this chapter, we'll discuss the technical details

which are happening "behind the scenes" You

don't need to know this information when you are

programming in BASIC. In fact, you won't even be

aware that these details are happening.

However, if you plan to write machine-language

disk programs or are simply interested in know-

ing all you can, you'll definitely want to read this

chapter. We'll begin by discussing how the Com-

puter organizes all the bytes on the disk. Then,

we'll show how to access them through machine-

language programming and other advanced

techniques.

WHAT ADISK CONTAINS

When you power-up the Computer, it organizes

the bytes on the disk into tracks and sectors. Some

of these bytes control the system. The great major-

ity of them are for data.

TVacks

The Computer organizes the disk into 35 tracks,

numbered 0-34. Each track contains approxi-

mately 6,250 bytes* 6,084 of them are divided into

sectors; the remaining are for system controls.

Byte# Contents

0-31 System controls

32-6115 Sectors

6116-6249* System controls

The system control bytes all contain the value of

4E (hexadecimal).

*the number of system control bytes at the end of

each track might vary slightly due to slight speed

variations.

Note: One byte contains 8bits. Each bit contains

either a1or a0. Normally, we express the contents of

these bits as ahexadecimal (base 16) number. For

example, if we say a byte contains the value of hexa-

decimal 4B, it contains this bit pattern —0100110.

kYou can find more information on hexadecimal and

binary number systems in amath textbook.

TECHNICAL INFORMATION

Sectors

Each track contains 18 sectors, numbered 1-18.

Each sector contains 338 bytes. 256 of them are for

data. The remaining bytes are for system controls.

Byte# Contents

0-55 System controls

56-311 Data

312-337 System controls

The hexadecimal contents of the system control

bytes are:

Byte# Hexadecimal Contents

0-7 00

8-10 F5

11 FE

12 Track Number

13 00

14 Sector Number

15 01

16-17 Cyclic Redundancy Check <CRC)

18-39 4E

40-51 00

52-54 F5

55 FB

312-313 Cyclic Redundancy Check (CRC)

314-337 4E

HOW THE DATA IS ORGANIZED

Each track contains 4,608 bytes which the Com-

puter can use for data:

18 sectors per track

x256 data bytes per sector

4,608 data bytes per track

The data bytes in the 17th track contain the disk's

directory. The data bytes in the remaining 34

tracks are for disk files:

Track #

0-16

18-34

Disk Files

Contents of Track's Data Bytes

Disk Files

Disk Directory

Disk Files

The Computer divides the 34 tracks for disk files

into 68 granules. Since each track contains two

granules, one granule is 2,304 bytes long:

9sectors in V2 track

x 256 data bytes per sector

2,304 bytes in agranule

The Computer uses granules to allocate space for

disk files in 2,304-byte clusters. Thus, if afile con-

tains 4,700 bytes, the Computer allocates 3gran-

ules (6,912 bytes) of disk space for it.

The location of the 68 granules, numbered 0-67, is

as follows:

Track 0, Sectors 1-9

Track 0, Sectors 10-18

Track 1, Sectors 1-9

Track 16, Sectors 10-18

Track 17, Sectors 1-18

Track 18, Sectors 1-9

Track 34, Sectors 10-18

Granule

Granule 1

Granule 2

Granule 33

Directory

Granule 34

Granule 67

Note: The minimum size of adisk file is one granule

or 2,304 bytes. Adi.sk will hold amaximum of68 disk

files.

Disk Directory

The directory track (track 17) contains afile allo-

cation table and directory entries. The sectors on

this track which contain this information are:

Sector #Contents

2File allocation table

3-11 Directory entries

The remaining sectors in the directory track are

for future use.

Directory Entries

The 9sectors of the directory containing directory

entries (sectors 3-11) will hold up to 72 entries.

Each entry is 32 bytes long and contains:

TECHNICAL INFORMATION

Byte #Contents

0-7 Filename, left justified, blank-filled.

If byte =0, the file has been deleted

and the entry is available.

If byte =FF (hexadecimal), the

entry (and all following entries) have

not yet been used.

8-10 Filename extension, left justified,

blank-filled.

11 File Type

=BASIC program

1=BASIC data file

2=Machine-language program

3=Text Editor source file

12 ASCII flag

=the file is in binary format

FF (hexadecimal) =the file is in

ASCII format

13 The number of the first granule in the

file (0-67).

14-15 The number of bytes in use in the last

sector of the file.

16-31 Reserved for future use.

File Allocation Table

Sector 2of the directory contains afile allocation

table for each of the 68 granules on the disk. This

information is located on the first 68 bytes of the

sector. The remaining bytes contain zeroes:

Byte #Contents

0-67 Granule information

68-255 Zeroes

Each of the first 68 bytes corresponds with agran-

ule. For example, byte 15 corresponds with gran-

ule 15.

These bytes will either contain avalue of FF, 0-43,

or C0-C9 (hexadecimal):

FF The corresponding granule is free. It is

not part of adisk file.

00-43 The corresponding granule is part of a

disk file. The value, converted to dec-

imal, points to the next granule in the

file. For example, if the value in abyte

is 0A, 10 is the next granule in the file.

C0-C9 The corresponding granule is the last

granule in the file. The value contained

in bits 0-5 of this byte tells how many

of the sectors in that granule are part

of the disk file. (Bits 7and 8both equal

1.)

SKIP FACTOR

The Computer reads or writes data to the disk one

sector at atime. Between sector reads or writes, it

does some processing.

The disk does not stop and wait for the Computer

to do this processing. It spins continuously.

For example, the Computer might read Sector 1

first. But by the time it's finished processing Sec-

tor 1, the disk will have spun to Sector 6.

To allow for this time differential, the Computer

sets a"skip factor" of 4when it formats the disk.

This notes on the disk that the computer should

skip 4"physical" sectors between each "logical"

sector:

PHYSICAL LOGICAL

SECTOR SECTOR

212

416

713

917

10 10

11 3

12 14

TECHNICAL INFORMATION

PHYSICAL LOGICAL

SECTOR SECTOR

13 7

14 18

15 11

16 4

17 15

18 8

JSR [$C004]

Thus, after reading Sector 1, the Computer will

skip "physical" sectors 2, 3, 4, and 5. The second

"logical" sector it reads will be "physical" Sector 6.

Askip factor of 4 is the optimum setting for

BASIC LOADs and SAVEs. However, if you're not

using BASIC, you might be able to use afaster

skip factor. For example:

DSKINI 0r 3

tells the Computer to skip 3physical sectors

between each logical sector.

.Vote: It's difficult to determine the optimum skip fac-

tor. We recommend you leave it at 4unless you have

agood understanding of how it works.

MACHINE-LANGUAGE DISK

PROGRAMMING

The disk system contains amachine-language

routine called DSKCON which you can call for all

disk input/output operations. To call this routine,

you need to write instructions to the Color Com-

puter's 6809 Microprocessor.

See "Using Machine-Language Subroutines" with

Color BASIC in Getting Started with Color BASIC

for the procedures to use in accessing amachine-

language subroutine. See 6809 Assembly Lan-

guage Programming, by Lance Leventhal

(published by Osborne/McGraw-Hill) for the spe-

cific 6809 instructions.

Information on DSKCON

DSKCON's entry address is stored in locations

C004 and C005 (hexadecimal). You can call it with

this assembly-language instruction:

DSKCON's parameters are located in six memory

locations, organized as follows:

DCOPC RMB 1

DCDRV RMB 1

DCTRK RMB 1

DSEC RMB 1

DCBPT RMB 2

DCSTA RMB 1

The address of the first, DCOPC, is contained in

locations C006 and C007 (hexadecimal). You can

use the first five memory locations to pass param-

eters to DSKCON. DSKCON returns astatus byte

to the sixth location, DCSTA.

These are the parameters you can pass to the first

five memory locations:

DCOPC —Operation Code

=Restore head to track

1=No operation

2=Read sector

3=Write sector

DCDRV —Drive Number

to 3

DCTRK —Track Number

to 34

DCSEC —Sector Number

1to 18

DCBPT —Buffer Pointer

the address of a256-byte buffer. For read

sector, the data is returned in the buffer.

For write sector, the data in the buffer is

written on the disk.

This is the meaning of the status byte which the

DSKCON routine returns to location DCSTA:

DCSTA —Status

Bit 7=1Drive Not Ready

Bit 6=1Write Protect

Bit 5=1Write Fault

Bit 4=1Seek Error or Record Not

Found

Bit 3=1CRC Error

Bit 2=1Lost Data

TECHNICAL INFORMATION

If all the bits contain 0, no error

occurred. (See the disk service manual

for further details on the error bits)

After returning from DSKCON, you can turn off

the drive motor by putting the value of in the

memory location FF40 (hex).

Sample Programs Using DSKCON

This program uses DSKCON to restore the head

to track 0:

RLDX $C00G SET XAS APOINTER TO THE

PARAMETERS

CLR ,){ DCOPC =0 FOR RESTORE

LDA 9\ DCDRO =1 TO SELECT DRIVE

ONE

STA 1»x

JSR ttcoaa] CALL DSKCON

IDA #$0Q TURN OFF THE DRIVE MOTOR

STA $FF40

TBT GtX CHECK FOR ERRORS

BNE ERRORS GO REPORT THE ERRORS

RTS

LDA *$i)5 "E" FOR ERROR

STA *41D TOP RIGHT OF THE DISPLAY

RTS

This program uses DSKCON to read track 3, sec-

tor 17 of drive into memory locations 3800

through 38FF:

LDX $C00B

LDA *2

STA ,X

CLR 1tX

LDA «3

STA 2,X

LDA *17

STA 3.X

LDU **3B00

SET XAS APOINTER TO THE

PARAMETERS

DCOPC =2FOR READ ASECTOR

SELECT DRIVE

SELECT TRACK 3

SELECT SECTOR 17

DCBPT=3B00(HEX) FOR

STORING DATA

STU a,x

JSR [*C004] CALL DSKCON

LDA »$00 TURN OFF THE DRIVE MOTOR

STA SFF40

TST BtX CHECK FOR ERRORS

BNE ERRORS GO REPORT THE ERRORS

RTS

LDA **45

STA $aiD

RTS

"E" FOR ERROR

TOP RIGHT OF THE DISPLAY

CNote: DSKCON preserves the contents ofall registers

except CC.

You can write asimilar program to write to asec-

tor by setting DCOPC to 3instead of 2.

Saving aMachine-Language

Program

You can use the SAVEM command to store a

machine-language program on disk. You need to

specify where in memory the program resides (its

starting and ending addresses). You also need to

specify the address where it should be executed.

Use the hexadecimal numbers for all of these

addresses.

For example, let's assume you have amachine-

language program which resides in addresses

5000-5FFF of memory. The address where it

should be executed is 500A. You would store this

program on disk by typing:

SAVEM "PROG/MAC" >&H5000 ,&H5FFF ,1H500A

To load it back into memory, you could use the

LOADM command:

LOADM "PROG/MAC"

This would load "PROG MAC" back into memory

locations 5000-5FFF. The Computer would begin

executing it at location 500A.

If you want to load it into adifferent memory loca-

tion, you could specify an offset address to add to

the program's loading address. For example:

LOADM "PROG/MAC" ,1000

would load "PROG/MAC" into memory locations

6000-6FFF. The Computer would begin executing

it at address 600A.

TECHNICAL INFORMATION

SPECIAL INPUT/OUTPUT

COMMANDS

BASIC offers two special input/output commands.

These commands input and output data directly to

aparticular sector. They do this through bypass-

ing the entire disk's filing system.

The first, DSKI$, inputs the data from the sector

you specify. This is its format:

DSKI$ drive number, track, sector, string vari-

ablel, string variable2

The first 128 bytes of the sector are input into

string variablel. The second 128 bytes are input

into string variable2. For example:

50 EXT$(0)

DSKI$ 0, 17, 1,A*, B$ (ENTER)

inputs the contents of sector 1, track 17 of the disk

in drive 0. It inputs the first 128 bytes into A$ and

the second 128 bytes into B$. After typing this

command, you can display the contents of this sec-

tor with:

PRINT A$i B$ (ENTER)

Since DSKI$ will read any sector on the disk, it is

the only BASIC command which will read the

directory sector. This sample program uses DSKI$

to search the directory for filenames with the

extension "DAT":

10 FOR X=3TO 11

20 DSKI$ 0,17»X»A$»B$

30 C$ =A$ +LEFT$(B$»127)

40 NAH$(0) =LEFT$(C$,8)

=MID*(C*,9,3)

TO 7

=MID$(C*»N*32+1 ,8)

=MID$(C$,9+N*32»3)

FOR N=l

70 NAM*(N)

80 EXT$(N)

90 NEXT N

100 FOR N=0 TO 7

110 IF EXT$(N) ="DAT" AND

LEFT*(NAM$(N) ,1)<>CHR$(0) THEN PRINT

NAM$(N)

120 NEXT N

130 NEXT X

The second command, DSKO$, outputs data

directly to the sector you specify. Since it bypasses

the disk filing system, it will output data without

opening afile and listing its location in the direc-

tory. For this reason you need to be careful:

1. not to output data over the directory sectors

unless you no longer plan to use the directory.

2. not to output data over other data you presently

have stored on the disk.

The format of DSKO$ is:

DSKO$ drive number, track, sector, stringl,

string2

Stringl will go in the first 128 bytes of the sector.

String2 will go in the next 128 bytes. For example:

DSKO* 0, 1. 3, "FIRST STRING", "SECOND

STRING" (ENTER)

Outputs data to sector 3, track 1, on the disk in

drive 0. "FIRST STRING" will go in the first 128

bytes of this sector. "SECOND STRING" will go in

the second 128 bytes.

AIPDPEMMIXEi

APPENDIX A.

PROGRAMMING EXERCISE

ANSWERS

PROGRAMMING EXERCISE #5-1

10 PRINT: PRINT "CHECKS FOR CAR EXPENSES"

20 OPEN "I" ,*1 ."CHECKS"

30 IF E0F( 1) =-1 THEN 100

40 INPUT *1 ,A$,B,C$

50 IF C$ ="CAR" THEN 70

60 GOTO 90

70 PRINT: PRINT "CHECK PAYABLE T0:"iA$

80 PRINT "AMOUNT:" SB

90 GOTO 30

100 CLOSE *1

PROGRAMMING EXERCISE #6.1

10 OPEN "I" ,«1 t"ANIMALS/DAT"

20 OPEN "0"

»2 >"NEW/DAT"

30 IF EOF(l) =-1 THEN 70

40 INPUT *1 .A*

50 WRITE «2i A*

G0 GOTO 30

70 CLOSE «1: CLS

80 PRINT "INPUT ANIMALS YOU WANT TO ADD"

90 PRINT "PRESS <ENTER> WHEN FINISHED"

100 INPUT A*

110 IF A* ="" THEN 140

120 WRITE «2, A$

130 GOTO 80

140 CLOSE *2

150 KILL "ANIMALS/DAT"

160 RENAME "NEW/DAT" TO "ANIMALS/DAT"

PROGRAMMING EXERCISE #6.2

10 OPEN "I" .*1 ,"ANIMALS/DAT"

20 OPEN "0" ,#2. "NEW/DAT"

30 IF EOF(l) =-1THEN 100

40 INPUT *1 ,A$

50 PRINT: PRINT A$

60 INPUT "DO YOU WISH TO DELET

70 IF R$ ="YES" THEN 90

80 WRITE *2, A$

90 GOTO 30

1021CLOSE *1

HE1CLOSE *2

1201KILL "ANIMALS/DAT"

1301RENAME "1NEW/DAT" TO "ANIMA

THIS" R$

PROGRAMMING EXERCISE #6.3

10 CLS: PRINT

20 PRINT "(1)

"DO YOU WISH TO --

STORE ANEW FILE"

30 PRINT "(2) SEE THE FILE"

40 PRINT "(3) END"

50 INPUT 01

60 ON 01 GOTO 80. 130, 420

70 GOTO 10

80 OPEN "0". tli "MEMBERS/DAT"

90 1:OSUB 430

100 IF N$ ="" THEN CLOSE *1: GOTO 10

110 WRITE *1 ,N$, A$. P$

120 GOTO 90

130 OPEN "I" ,*1 ,"MEMBERS/DAT"

140 OPEN "0" i*2i "TEMP/DAT"

150 CLS :INPUT "DO YOU WANT TO CHANGE THE

FILE"! 02$

160 IF EOF(l) =-1 THEN 320

170 INPUT *li N$. A* ,P$

180 PRINT: PRINT "NAME :" N$

190 PRINT "ADDRESS :" A$

200 PRINT "TELEPHONE :" P$

210 IF 02$ ="NO" THEN 300

220 PRINT: PRINT "DO YOU WISH TO:"

230 PRINT "1) CHANGE THE ADDRESS?"

240 PRINT "2) DELETE THE MEMBER?"

250 PRINT "3) GO ON TO THE NEXT MEMBER?"

2G0 INPUT N

270 ON NGOTO 290. 160, 300

280 GOTO 230

290 INPUT "INPUT NEW ADDRESS"! A$

300 WRITE *2, N$» A$, P$

310 GOTO 160

320 PRINT: INPUT "DO YOU WISH TO ADD ANEW

MEMBER" i03$

330 IF 03$ ="NO" THEN 380

340 GOSUB 430

350 IF N$ ="" THEN 380

360 WRITE #2, N$, A$, P$

370 GOTO 340

380 CLOSE *1 .*2

390 KILL "MEMBERS/DAT"

400 RENAME "TEMP/DAT" TO "MEMBERS/DAT"

410 GOTO 10

420 END

430 CLS: PRINT "PRESS <ENTER> WHEN FINISHED

:PRINT

440 INPUT "NAME OF MEMBER:" iN$

450 IF N$ ="" THEN 480

460 INPUT "ADDRESS:"! A$

470 INPUT "PHONE NUMBER:" iP$

480 RETURN

PROGRAMMING EXERCISE 7.1

10 OPEN "D"

«1. "NAMES/DAT

20 WRITE «1 ,"J. DOE"

30 PUT *1 ,2

31 WRITE *1 ,"BILL SMITH"

32 PUT *1 ,3

34 GET «1 ,3

36 INPUT *1 .A$

38 PRINT A$

40 CLOSE *1

.APPENDIX A

PROGRAMMING EXERCISE 7.2

This produces an FD —Bad File Data —error in line

36. The first field in record 2 is "FLIES," astring. Line

36 INPUTs it into N, anumeric variable.

PROGRAMMING EXERCISE 7.3

10 OPEN "D" ,«1 ,"NAMES/DAT"

20 GOTO 70

30 FOR X=1TO 10

40 PRINT: PRINT "RECORD" X

50 GOSUB 180

G0 NEXT X

70 INPUT "WHICH RECORDd-10)"

80 IF X>10 THEN 170

80 IF X <1THEN END

100 GET #1 iX

110 INPUT *li N*. A*. C»i S$i

120 PRINT: PRINT "RECORD" X

130 PRINT N*, ,A*,.C*,,S*,,Z*

140 INPUT "DO YOU WANT TO CHANGE THIS"! R*

150 IF R* ="YES" THEN GOSUB 180

1B0 GOTO 70

170 CLOSE «1: END

180 INPUT "NAME" iN*

"ADDRESS "i A$

'CITY :"i C$

'STATE: 1'! S*

'ZIP :"i Z*

N*. A*. C$i

190 INPUT

200 INPUT

210 INPUT

220 INPUT

230 WRITE »1

240 PUT «1 ,X

250 RETURN

S*: 1$

PROGRAMMING EXERCISE #9.1

10 OPEN "D" ,81 ,"MAIL/DAT" ,57

20 FIELD 81,15 AS LAST*. 10 AS FIRST*, 15 AS

ADDRESS* .10 AS CITY* ,2 AS STATE* .5 AS ZIP*

+130 R=R

40 CLS

50 INPUT

G0 INPUT

70 INPUT

80 INPUT

90 INPUT

100 INPUT

110 LSET LAST*

120 LSET FIRST*

LAST NAME'SL*

FIRST NAME" iF*

ADDRESS" !A*

CITY" iC*

STATE" iS*

"ZIP CODE"iZ*

140 LSET CITY* =C*

150 LSET STATE* =S*

160 LSET ZIP* =Z*

170 PUT #1 ,R

180 PRINT

190 INPUT "MORE DATA( Y/N) "iAN*

200 IF AN* ="Y" THEN 30

210 CLOSE *1

PROGRAMMING EXERCISE #9.2

10 OPEN "D"i «1. "MAIL/DAT". 57

20 FIELD *1. 15 AS LAST*, 10 AS FIRST*:,15 AS

ADDRESS*. 10 AS CITY*. 2AS STATE*, 5AS ZIP*

30 R=R+1

40 CLS

50 GET *1 ,R

60 PRINT LAST* "," FIRST*

70 PRINT ADDRESS*

80 PRINT CITY* "." STATE*

90 PRINT ZIP*

100 PRINT

110 IF LOF(l)=R THEN 140

120 INPUT "PRESS <ENTER> FOR NEXT NAME"'!E*

130 GOTO 30

140 CLOSE #1

PROGRAMMING EXERCISE #9.3

,5 AS POP*

10 OPEN ''D" ,#1 ."POP" .15

20 FIELD *1 ,10 AS COUNTRY*

30 R=R+1

40 CLS

50 INPUT "COUNTRY" !C*

60 INPUT "POPULATION" !P

70 LSET COUNTRY* =C*

80 LSET POP* =MKN*(P)

85 PUT *1 ,R

90 PRINT

INPUT "MORE DATA(Y/N)'100

110 IF AN* =

120 CLOSE *1

iAN*

"Y" THEN 30

PROGRAMMING EXERCISE #9.4

10 OPEN "D" ,#1 ,"POP" ,15

20 FIELD «1 .10 AS COUNTRY*,

30 R=R+1

40 GET 81 ,R

50 PRINT COUNTRY*,

5AS POP*

CON (POP*)

130 LSET ADDRESS* A*

IF LOFUJOR

CLOSE 81

THEN 30

APPENDIX B.

CHAPTER CHECKPOINTANSWERS

CHAPTER 2

1. Unless the disk has been formatted, there is no way

to locate any given area on the disk.

2. The disk directory is an index of the names, loca-

tions, and types of all the files on the disk.

3. Adisk file is an individual block of information

stored on the disk, under afilename.

4. Information stored in memory will only be there

temporarily. It will be destroyed if the Computer is

turned OFF or if you execute aNEW, LOAD, DIS-

KINI, BACKUP, or COPY command. (We'll discuss

BACKUP and COPY in the next chapters). Infor-

mation stored on disk will be there permanently. It

won't be destroyed if the Computer's turned off or if

memory is cleared. (Don't leave adisk in the drive

when you turn the Computer off. We'll explain why

in the next chapter.)

5. The only way to change the contents of adisk file is

by storing different information under the same

filename.

CHAPTER 3

1. Turning the Computer ON or OFF while the disk is

in its drive may damage the disk.

2. Only felt tip pens may be used to write on the disk's

label. Hard point pens and pencils may damage the

disk and garble the information on it.

3. Error messages tell you that something is wrong

with either the program you are running or the last

command that you used.

4. "Write-protecting" is away of protecting your disks

from alteration. It is done by putting agummed label

over the write-protect notch. You can read from a

"write-protected" disk, but you can't write to it.

5. On aone-drive system, insert the source disk into the

drive and type BACKUP0 (ENTER) .The Computer will

ask you to insert the destination disk and press

(ENTER) .This procedure is repeated until the Com-

puter prints OK. On amulti-drive system, type the

BACKUP command specifying the drive number

with the source disk and the destination disk. For

example, BACKUP TO 1backs up the source disk

(in Drive 0) to the destination disk (in Drive 1).

CHAPTER 4

1. Afile can be renamed with the RENAME command.

For example, RENAME "OLDFILE/NAM" TO

"NEWFILE/NAM" renames OLDFILE/NAM to

NEWFILE/NAM. You must specify the extension for

both filenames so the Computer can find them.

2. You can find out how much space you have remain-

ing on the disk by typing PRINT FREE ()(ENTER) .This

will tell you the number of granules left on the disk

in Drive 0. If you are running out of granules, you

might want to KILL afew files or switch to another

disk.

3. Unless otherwise specified, the Computer always

uses Drive 0. This can be changed by typing DRIVE

1, which enables you to access Drive 1without hav-

ing to specify the number in your command, (i.e.,

now DIR and DIR1 would both get you the directory

of the disk in Drive 1.

CHAPTER 5

1. Buffer #1 is atemporary storage area for informa-

tion going between the disk and memory.

2. Adisk file must be OPENed before any information

can go between the disk and memory.

3. Adisk must be CLOSEd so that the information still

in the buffer will end up where it's supposed to and

so that the file can be reopened. All files must be

closed before you switch disks.

4. Afile OPENed for input allows information to go

from the disk file into the memory of the Computer.

Afile OPENed for output allows information to go

from memory to the disk file.

CHAPTER 6

1. When you OPEN a"sequential access" file, you can

only OPEN it for "I" or "O"—not both. You can't out-

put to afile opened for "I," nor can you input from a

file opened for "O."

2. No. The file must first be closed and then reopened

for input.

.APPENDIX B

CHAPTER 7

1. Records are equal-sized divisions in your disk file

where you can put your data. Since each is the same

size, the Computer can use them to access your data

directly.

2. Fields are subdivisions of records.

3. In asequential access file, the only locations the

Computer knows are the beginning and ending of

the file. In adirect access file, it can determine where

each individual record is (by the size of the records).

4. Since each record of the file has aknown location, the

Computer can access it without going through the

preceding parts of the file, as it would if the file was

sequential.

5. Acomma causes the Computer to space over to the

next print column before printing another data item.

6. Asemicolon causes the Computer to print the data

items immediately next to each other.

7. Astring is printed simply as the string itself. It is not

enclosed in quotation marks.

CHAPTER 9

1. The Computer will set the record length at 256 bytes.

2. The data must have afield with aspecific length for

it to be LSET This length is assigned in the FIELD

line.

3. MKN$ converts anumber into a5-byte coded string.

CHAPTER 8

1. The minimum size of adisk file is 2,304 bytes (one

granule). Since the Computer allocates disk space in

granules, afile can be no smaller than one granule.

2. The Computer first WRITEs the number's sign (a

minus sign if it's negative or ablank space if it's pos-

itive). Then it WRITEs the number itself. Immedi-

ately following the number, it WRITEs on trailing

blank space.

3. Astring is written with quotation marks around it.

4. INPUT inputs only the data items listed, while LINE

INPUT inputs everything up to the (ENTER) character.

CHAPTER 10

1. You must type an Aat the end of your SAVE com-

mand if you plan to ever MERGE it with aprogram

in memory.

2. The line number of the program saved on disk

prevails.

3. The Computer reserves two buffers when you power-

up.

4. The Computer reserves atotal of 256 bytes of buffer

space when you power-up.

5. FILES 3, 3000 get the Computer to reserve 3buffers

with atotal of 3000 bytes of buffer space.

APPENDIX C.

SAMPLE PROGRAMS

SAMPLE PROGRAM #1

BALANCING YOUR CHECKBOOK

This program creates amaster disk file which contains

all your checks and deposits for the entire year. You can

print them out by the month or the year. If you want to

use your printer, change the appropriate PRINT lines

to PRINT #-2. (See Chapter 21 in Getting Started

with Color BASIC).

10 'Checkbook Program

20 '

30 'This program provides a

recordofyour chec k s?

40 'deposits? and balances.

The checks can be labeled

50 'with an account number to

show to what expense

60 'they were paid* such as

medical ?rent ?food? etc

70 'The program uses direct

addressing? each file record

80 'being 40 bytes long? and

formatted as follows! 8

90 'bytes for the date? 4bytes

for the check or deposit

100 'slip number? 20 bytes for

the recipient of the check

110 73bytes for the account

number? and 5bytes for the

120 'amount of the check or

deposi t

130 '

140 CLEAR 1000

150 DIM CHK*<50)

160 CLS

170 PRINT 3107? "SELECTIONS:"

180 PRINT a162? "1) ADD CHECKS

TO YOUR FILE"

190 PRINT a194? "2) LIST YOUR

CHECKS? DEPOSITS?

200 PRINT a229? "AND BALANCES"

230 PRINT 3322? "3) END JOB?"

240 PRINT a394? "(1?2? OR 3>"

250 AN*= INKEY*

260 IF AN*="" THEN 250

270 ON VAL(AN*) GOSUB 310? 700?

1080? 1560

280 GOTO 160

290 '

300 '

31'This subroutineinputs

the data.

320 '

330 OPEN "D" ?#1 ?"CHECKS/DAT" ?40

340 FIELD #1?8 AS DATE*? 4AS CHNO*?

20 AS PDTO*? 3AS ACNO*? 5AS AMT*

350 REC =L0F<1)

360 REC =REC +1

370 CLS

380 PRINT a 64? "CHECK OR

DEPOSIT (C/D)"

390 AN* =INKEY*

400 IF AN* ="D" THEN 430

410 IF AN* ="C" THEN 490

420 GOTO 390

430 INPUT "DEPOSIT DATE

(MM/DD/YY)";D*

440 INPUT "DEPOSIT SLIP NUMBER

<NNNN )";C*

450 P* ="

460 INPUT "ACCOUNT NUMBER* NNN) "? A*

470 INPUT "AMOUNT OF DEPOSIT" 5AMT

480 GOTO 550

490 INPUT "CHECK DATE (MM/DD/YY) ";D*

500 INPUT "CHECK NUMBER <NNNN >"? C*

510 INPUT "PAID TO" ?P*

520 INPUT "ACCOUNT NUMBER <NNN) ";A*

530 INPUT "AMOUNT OF CHECK"; AMT

540 AMT =-AMT

550 LSET DATE* =D*

560 LSET CHNO* =C*

570 LSET PDTO* =P*

580 LSET ACNO* =A*

590 LSET AMT* =MKN* (AMT

)

600 PUT #1?REC

61.0 PRINT 3320? "MORE INPUT(Y/N)"

620 AN* =INKEY*

630 IF AN* ="N" THEN 660

640 IF AN* ="Y" THEN 360

650 GOTO 620

660 CLOSE #1

670 RETURN

680 '

690 '

700 'This subroutine balances the

checkbook and outputs the results.

710 '

720 OPEN "D" ?#1 ?"CHECKS/DAT" ?40

730 FIELD #1,8 AS DATE*? 4AS CHNO*?

20 AS PDTO*? 3AS ACNO*? 5AS AMT*

740 CLS

750 PRINT 3160? "DO YOU WANT A

LISTING FOR AMONTH OR FOR THE"

760 PRINT 3192? "WHOLE YEAR? (Y/M)"

770 INPUT A*

780 IF A* ="M" THEN PRINT 3254?

-APPENDIX C

"WHAT MONTH(MM)" :INPUT MN*

790 BAL =

800 FOR REC =1TO LOF (

)

810 GET #1,REC

820 BAL =BAL +CVN(AMT*)

830 IF A* ="M" AND LEFT*< DATE** 2)

<> MN* THEN 1030

840 CLS

850 IF PDTO* ="

THEN 930

860 PRINT a645 "DATE OF CHECK:":

PRINT a84, DATE*

870 PRINT "CHECK NUMBER: ": PRINT

3116,CHN0*

880 PRINT "PAID TO:" ."PRINT a

148, PDTO*

890 PRINT a160> "ACCOUNT NUMBER:":

PRINT 3180,ACNO*

900 PRINT "AMOUNT OF CHECK: ": PRINT

3211, USING "**###.##" ;-CVN<AMT*>

910 PRINT "BALANCE:" :PRINT a243,

USING "**###„##"*; BAL

920 GOTO 980

930 PRINT:PRINT:PRINT "DATE OF

DEPOSIT:" SPRINT 385, DATE*

940 PRINT "DEPOSIT SLIP NUMBER:":

PRINT 3117,CHN0*

950 PRINT "ACCOUNT NUMBER: ": PRINT

3149,ACN0*

960 PRINT "AMOUNT OF DEPOSIT:":

PRINT a180, USING "**###.##";

CVN<AMT*>

970 PRINT "BALANCE:" :PRINT a

212,US ING "**### .##''; BAL

980 PRINT a256, "PRESS <ENTER>

FOR NEXT RECORD OR <R> TO RETURN

TO 'SELECTIONS'"

990 AN* =INKEY*

1000 IF AN* =CHR*(13) THEN 1030

1010 IF AN* ="R" THEN 1040

1020 GOTO 990

1030 NEXT REC

1040 CLOSE #1

1050 RETURN

1540 '

1550 '

1560 'This subroutine terminates

the pro gram.

15 70 '

1580 END

SAMPLE PROGRAM #2

SORTING YOUR CHECKS.

This subroutine will be especially helpful at tax time.

It takes the checks file which you created in "Sample

Program #1" and sorts all the checks by account. Want

to know exactly how much you spent on medical bills

(or business expenses, contributions, etc.)? This pro-

gram will let you know right away.

210 PRINT a258, "3) SORT YOUR

CHECKS BY"

220 PRINT 3293, "ACCOUNT NUMBER?"

230 PRINT a322, "4) END JOB?"

240 PRINT 3394, "(1,2, 3, OR 4)"

270 ON VAL(AN*> GOSUB 310,700.

1080, 1560

1060 '

1070 '

1080 'This subroutine sorts the

checks from those with the

1090 'smallest account numbers

to the largest account numbers

1100 'using a"bubble sort".

Each check is handled as one

1110 'data string to make the

swaps easier.

1120 '

1130 OPEN "D",#l, "CHECKS/DAT", 40

1140 FIELD #1,40 AS INFO*

1150 FOR 1=1 TO LOF(l)

1160 GET #1,

1170 CHK*(I) =INFO*

1180 NEXT I

1190 CNT =

1200 FOR I=1TO LOFU) -1

1210 IF MID*(CHK*(I),33,3> <=

MID*<CHK*<I+1),33,3> THEN 1260

1220 TEMP* =CHK*(I)

1230 CHK*<I) =CHK*<I+1)

1240 CHK*(I+1) =TEMP*

1250 CNT =1

1260 NEXT I

1270 IF CNT =1THEN 1190

1280 CLS

1.290 PRINT 3194, "WHAT ACCOUNT

NUMBER (NNN/ ALL)"

1300 INPUT AN*

1310 FOR I=1TO LOF(l

)

1320 IF AN* <> "ALL" AND AN* <>

MID*(CHK*<I>,33,3) THEN 1510

1330 CLS

1340 PRINT 366, "ACCOUNT NUMBER:"

:PRINT a85,MID*(CHK*(I),33,3>

1350 IF MID*(CHK*(I ), 13,20) =

"THEN 1410

1360 PRINT a98, "DATE OF CHECK:":

PRINT a117,LEFT*<CHK*(I),8)

1370 PRINT 3130, "CHECK NUMBER:"

:PRINT a149,MID*<CHK*<I),9,4)

1380 PRINT a162, "PAID TO:":

APPENDIX C.

PRINT a181, MID*<CHK*(I>, 13,20)

1390 PRINT 3194 i"AMOUNT OF CHECK:

PRINT a212, USING "**###.##";

-CVN<RIGHT*<CHK*(I>,5)

)

1400 GOTO 1440

1410 PRINT a98? "DATE OF DEPOSIT:"

PRINT a117,LEFT*<CHK*<I>,8)

1420 PRINT 3130, "DEPOSIT NUMBER:"

PRINT a149,MID*<CHK*(I),9,4>

1430 PRINT 3162* "AMOUNT

OF DEPOSIT: "

PRINT 3180 ,USING "**###.

CVN<RIGHT*(CHK*<I>,5> )

1440 PRINT 3290, "(PRESS

TO SEE NEXT"

1450 PRINT 3322? "RECORD OR <R> TO

RETURN TO"

1460 PRINT 3354, "'SELECTIONS' )"

A2* =INKEY*

IF A2* =CHR*<13>

IF A2* ="R" THEN

GOTO 1470

##"

<ENTER

1470

1480

1490

1500

THEN

1520 1510

1510 NEXT I

1520

1530 CLOSE #1

RETURN

SAMPLE PROGRAM #3

MEMBERSHIP LIST

Want to store the names and telephone numbers of all

your club members? This program puts them all in a

disk file in alphabetical order. Add a few lines to it, and

it will store their addresses and phone numbers also.

10 'Create list and alphabetize.

20 '

30 'The object of this program

is to create afile of

40 'alphabetically arranged names

and phone numbers. The

50 'names and numbers are first

input into an array, ARRAY* (I)

60 'then put into alphabetical

order, and finally put into

70 'adisk file called "NAMES/NOS".

The file is 35 bytes

80 'lor.9, all of it allotted to

one variab 1e, INFO*. The

90 'file can be added to anytime

afterit s c reationan d will

100 'automatically be alphabetised.

The program can be used

110 'in conjunction with the "Search

a1ist"program(sampl

120 'program #4)

130 7

140 CLEAR 1050

150 DIM ARRAY*<30)

160 OPEN "D",#l, "NAMES/NOS", 35

170 FIELD #1,35 AS INFO*

180 •}

190 'First the file is checked

to 2:.ee if there are any

200 'records currently on it.

210 t

220 IF L0F(1) =THEN 1=1: GO TO 310

230 FOR 1=1 TO LOF(l)

240 GET #1,1

250 ARRAY* U) =INFO*

260 NEXT I

270 t

280 'The new names and numbers

are input and then concatenated

290 into 1stringi ARRAY* (I)

300 •J

310 CLS

320 PRINT a64

330 INPUT "LAST NAME"?L*

340 INPUT "FIRST NAME" 5F*

350 INPUT "MIDDLE INITIAL" ;M*

360 INPUT "AREA CODE" 5A*

370 INPUT "PHONE NUMBER" ?P*

380 ARRAY*(I) =LEFT*<L*+" ,"+F*+" "

+M*+" ",24)+A*+P*

390 PRINT a288, "MORE DATA <Y/N>?"

400 AN* =INKEY*

410 IF AN* ="Y" THEN 1=1+1 :

GOTO 310

420 IF AN* ="N" THEN 470

430 GOTO 400

440 •>

450 'Then, ARRAY*(I) is put into

al ptiabetical order.

460 '

470 FOR J=l TO I

480 FOR K=J TO I

490 IF ARRAY* (J)

THEN 530

ARRAY* (K)

500

510

520

530

540

55'

560 '

fer r ed

570 '

580 FOR N=l TO

590 L.SET INFO*

600 PUT #1,N

TEMP* =ARRAY* <J)

ARRAY*(J) =ARRAY*(K)

ARRAY* <K> =TEMP*

NEXT K

NEXT J

Fi nal 1y,the list

into "NAMES/NOS".

tran s -

ARRAY* (N)

.APPENDIX C

610 NEXT N

620 CLOSE #1

630 END

SAMPLE PROGRAM #4

SEARCH FOR ANAME

Since the file you created in "Sample Program #3" is

already in alphabetical order, you can immediately

find the name you want. This program shows how.

10 'Search a1ist

20 '

30 '(NOTEs This program requires

that afile called "NAMES/NOS

40 'exists —see "Create list and

alphabetize —Sample program #3)

50 'This program searches adisk

file which holds names and

60 'phone numbers in alphabetical

order. The file is adirect

70 'access file called "NAMES/NOS",

is 35 bvtes long* and

80 'is formatted as follows: 24

bvtes for the name; 3bvtes

90 'for the area code? 8bvtes

for the phone number. The

100 'program uses iterative

searching.

110 '

120 OPEN "D",#l, "NAMES/NOS" ,35

130 FIELD #1,24 AS NAME*, 3AS

AREA*, 8AS PHONE*

140 CLS

150 PRINT 399 ,"ENTER NAME(LAST,

FIRST MI)

160 LINE INPUT NM*

170 '

180 'Initialization of variables

190 *

200 Nl* =NM*

210 IF LEN(NM*> <24 THEN 800

220 IF LEN(NM*) >24 THEN 820

230 FIRST =1

240 MID -INT( (L0F(l)+l)/2)

250 LAST =LOF(l)

260 CNT =

270 '

280 'Program checks the last

record first because it won't

290 'be checked in the regular-

300 '

310 GET #1,LAST

320 IF NAME* =NM* THEN 450

330 '

340 'Program keeps comparing NM*

with NAME* from record MID

350 'until NM* is found or enough

records have been seen

360 'to show that it isn't in

the file

370 '

380 GET #1,MID

390 IF CNT >(L0F(l)+l)/2 THEN 710

400 IF NAME* <NM* THEN 570

410 IF NAME* >NM* THEN 640

420 '

430 'When NM* is found it is

printed out

440 '

450 CLS

460 PRINT 3104, NAME*

470 PRINT a136, "(" ?AREA* 5" )" ;PHONE*

480 PRINT 3195, "PRESS <ENTER>

TO CONTINUE,

490 PRINT 3227, "ELSE PRESS <Q>

TO QUIT"

500 AN* =INKEY*

510 IF AN* ="Q" THEN CLOSE: END

520 IF AN* =CHR*(13) THEN 140

530 GOTO 500

540 '

550 'Subprogram for when NAME*<NM*

560 '

570 FIRST =MID

580 MID =(MID+LAS'D/2

590 CNT =CNT +1

600 GOTO 380

6.1.0 '

620 'Subprogram for when NAME*>NM*

630 '

640 LAST =MID

650 MID =<MID+FIRST)/2

660 CNT =CNT +1

670 GOTO 380

680 '

690 'Subprogram for when NM* is

not foun

700 '

710 CLS

720 PRINT 3100, Nl*;" NOT FOUND"

730 PRINT 3132, "TO TRY AGAIN

PRESS <ENTER>"

740 AN* =INKEY*

750 IF AN* =""THEN 740

760 GOTO 140

770 '

780 'Subprograms for modifving

NM* to a20 bvte string

APPENDIX C.

790 '

800 NM* =NM*+" "

810 GOTO 210

820 NM* =LEFT* (NM*, 24)

830 GOTO 220

SAMPLE PROGRAM #5

UPDATE THE LIST

Update anything you want in the file you created in

"Sample Program #3." You can do it in ahurry with

this program.

10 'Edit your names file

20 '

30 'The object of this program

is to edit the "NAMES/NOS" file

40 'from "Create list and alpha-

betize" (Sample program #3). The

50 'program can either retain a

record vchange one of the variables

60 'in that record? or delete the

record entirely from the file.

70 '

80 CLS

90 PRINT 3106, "SELECTIONS:"

100 PRINT 3I685 "1) EDIT RECORD"

110 PRINT a200, "2) DELETE RECORD"

120 PRINT 3232, "3) END JOB"

130 PRINT 3298, "1,2, OR 3"

140 AN* =INKEY*

150 IF AN*="" THEN 140

160 ON VAL(AN*) GOSUB 180,590,850

170 GOTO 80

180 OPEN "D",#1,"NAMES .NOS ",35

190 FIELD #1,24 AS NAME*, 3AS AREA*,

8AS PHONE*

200 FOR 1=1 TO LOF(l)

210 GET #1,

220 CLS

230 PRINT 368, "RECORD NUMBER:" ;I

240 PRINT a100, "NAME:" ;NAME*

250 PRINT a132, "AREA CODE:"; AREA*

260 PRINT 3 164, "PHONE NUMBER";

PHONE*

270 PRINT 3228, "EDIT THIS

RECORD? (Y/N)"

280 AN* =INKEY*

290 IF AN* ~"Y" THEN 320

300 IF AN* ="N" THEN 560

310 GOTO 280

320 PRINT 3260, "EDIT NAME? (Y/N)"

330 AN*= INKEY*

340 IF AN* ="N" THEN NM* =NAME*:

GOTO 400

350 IF AN* ="Y" THEN 370

360 GOTO 330

370 LINE INPUT "NEW NAME" ;NM*

380 IF LEN(NM*) <24 THEN NM* =

NM*+ GOTO 380 ELSE 390

390 IF LEN(NM*> >24 THEN NM* =

LEFT* (NM*, 24)

400 PRINT 3292, "EDIT AREA

CODE? (Y/N)"

410 AN* =INKEY*

420 IF AN* ="Y" THEN 450

430 IF AN* ="N" THEN A* =AREA* :

GO TO 460

440 GOTO 410

450 INPUT "NEW AREA CODE"; A*

460 PRINT 3324, "EDIT PHONE

NUMBER? (Y/N)"

470 AN* =INKEY*

480 IF AN* ="Y" THEN 510

490 IF AN* ="N" THEN P* =PHONE* :

GOTO 520

500 GO TO 470

510 INPUT," NEW PHONE NUMBER" ;P*

520 LSET NAME* =NM*

530 LSET AREA* =A*

540 LSET PHONE* =P*

550 PUT #1,1

560 NEXT I

570 CLOSE #1

580 RETURN

590 OPEN "D",#l, "NAMES. NOS", 35

600 FIELD #1,24 AS NAME*, 3AS AREA*,

8AS PHONE*

610 OPEN "D" ,#2, "TEMP/FIL",35

620 FIELD #2,24 AS TNAME*,3 AS

TAREA*, 8AS TPHONE*

630 FOR 1=1 TO LOF( 1

)

640 GET #1,1

650 CLS

6/.0 PRINT 368, "RECORD #";I

670 PRINT a100, "NAME: "5NAMF*

600 PRINT 3132, "AREA CODE:"; AREA*

690 PRINT a164, "PHONE NUMBER:";

PHONE*

700 PRINT 3228, "DELETE THIS

RECORD? (Y/N)"

710 AN* =INKEY*

720 IF AN* ="Y" THEN 800

730 IF AN* ="N" THEN 750

740 GOTO 710

.APPENDIX C

750 LSET TNAME* =NAME*

760 LSET TAREA* =AREA*

770 LSET TPHONE* =PHONE*

780 J=J+1

790 PUT #2, J

800 NEXT I

810 CLOSE

820 KILL "NAMES/NOS"

830 RENAME "TEMP/FIL" TO "NAMES/NOS"

840 RETURN

850 END

SAMPLE PROGRAM #6

GRADING TESTS

This program is ideal for teachers. It creates several

disk files of students and their test score. You can then

immediately find averages and standard deviation for

the entire class or for each individual student.

10 'Test pros ram

20 '

30 'The object of this, program

is to input several

40 'files —anames file and several

test files.

50 'The files can then he accessed

as desired and the

60 'test scores processed to find

averages and standard

70 'deviations. The files are all

sequential access files.

80 '

90 '

100 'Main module of program

110 '

120 DIM NAME* <30), GRADE <6, 30)

130 CLS

140 PRINT a107," SELECT IONS"

160 PRINT a164, M1) CREATE A

'NAMES' FILE"

170 PRINT a196, H2) ADD ANEW

TEST FILE"

180 PRINT a228, "3) PROCESS SCORES"

190 PRINT a260, H4) END"

210 PRINT a331, "1,2,3 OR 4"

220 AN*=INKEY*

230 IF AN*="" THEN 220

240 ON VAL<AN*) GOSUB 290,430,

640, 1430

250 GOTO 130

260 '

270 'This subroutine builds a

"NAMES" file.

280 '

290 OPEN "0",#1,"NAME/FIL"

300 CLS

310 PRINT a96, "ENTER NAME OF

STUDENT :

•

320 LINE INPUT NAME*

330 WRITE #1,NAME*

340 PRINT 3196, "(PRESS <ENTER> TO

ENTER" :PRINT 3228, "ANOTHER NAME,

PRESS <0>": PRINT a260, "TO QUIT)"

350 AN*=INKEY*

360 IF AN*="" THEN 350

370 IF AN*O"0" THEN 300

380 CLOSE #1

390 RETURN

400 '

410 'This subroutine builds test

files.

420 '

430 CLS

440 PRINT 364

450 INPUT "NUMBER OF NEW TEST

FILE";TF*

460 IF TF* ="THEN 450

470 TF* ="TEST" +TF*

480 OPEN "I",#1,"NAME/FIL"

490 OPEN "0",#2,TF*

500 IF EOF(l) THEN 560

510 INPUT #1,NAME*

520 PRINT "NAME:"?NAME*

530 INPUT "SCORE" ;SCORE

540 WRITE #2, SCORE

550 GOTO 500

560 CLOSE #1,#2

570 RETURN

580 '

590 'This subroutine inputs the

"NAMES" file and the

600 'desired test files and then

processes them either

610 'on aclass basis or an

individual basis, and

620 'then prints out the results.

630 »

640 OPEN "I",#1,"NAME/FIL"

650 IF EOF(l) =-1 THEN 690

660 Y=Y+1

670 INPUT #1,NAME*(Y)

680 GOTO 650

690 YEND =Y

700 CLOSE #1

710 CLS

720 PRINT 396

730 INPUT "HOW MANY TESTS ARE

THERE" 5N

APPENDIX C

740 FOR X=l TO N

750 TF* ="TEST" +RIGHT*(STR*( X),1

)

760 OPEN "I",#1,TF*

770 FOR Y»l TO YEND

780 INPUT #1,GRADE(X,Y)

790 NEXT Y

800 CLOSE #1

810 NEXT X

820 CLS

830 PRINT a130* "INDIVIDUAL TOTALS

OR CLASS"

840 INPUT "TOTALS (I/O"? AN*

850 IF AN* ="I" THEN 900

860 IF AN* ="C" THEN 1130

870 '

880 'This portion processes the

scores bv the student.

890 '

900 FOR Y=l TO YEND

910 CLS

920 PRINT a105>NAME*(Y)

930 PRINT a137 »"SCORES:"

940 STUTOT =

950 FOR X=l TO N

960 PRINT TAB(10) GRADE<X*Y>

970 STUTOT =STUTOT +GRADE(X»Y)

980 NEXT X

990 AVE(Y) =STUTOT /N

1000 NUM =

1010 FOR X=l TO N

1020 NUM =<AVE(Y) -GRADE <X» Y) >+2

+NUM

1030 NEXT X

1040 SD =SOR(NUM /N)

1050 PRINT USING ""/. /.##.##";

"AVERAGE: "?AVE(Y)

1060 PRINT USING "V. '/.

##.##";» STANDARD DEVIAT ION :";SD

1070 PRINT "PRESS <ENTER> TO SEE

NEXT NAME"

1080 AN* =INKEY*

1090 IF AN* =CHR*<13) THEN 1100

ELSE 1080

1100 NEXT Y

1110 CLS

1120 PRINT 3105? "NO MORE NAMES"

1130 GOTO 1350

1140 '

1150 'This portion processes the

scores bv the test number

1160 'for the whole class.

1170 '

1180 INPUT "WHICH TEST NUMBER" ?X

1190 CLS

1200 PRINT 34»"DATA FOR TEST

NUMBER ";

1210 PRINT »NAME" STAB <25) "SCORE"

1220 TTOT =

1230 FOR Y=l TO YEND

1240 TTOT =TTOT +GRADED Y>

1250 PRINT TABU) NAME*( Y) ;TAB<25)

GRADE(X»Y>

1260 NEXT Y

1270 AVE TTOT /YEND

1280 NUM =

1290 FOR Y=l TO YEND

1300 NUM =NUM +(AVE -GRADE <X,Y) H2

1310 NEXT Y

1320 SD =SQR(NUM /(YEND -1))

1330 PRINT: PRINT USING

""/ •/.#•/.•/.##.##"?

"AVERAGE FOR TEST #" ;X ;":"?AVE

1340 PRINT USING "7. "/.

##.##"; "STANDARD DEVIATION: "!SD

1350 PRINT: PRINT "PRESS <ENTER>

FOR MORE"

1360 PRINT "PROCESSING* <Q>

TO QUIT"

1370 AN* =INKEY*

1380 IF AN* =CHR*(13) THEN 820

1390 IF AN* ="Q" THEN 1400

ELSE 1370

1400 RETURN

1410 '

1420 'This subroutine terminates

the program.

1430 '

1440 END

SAMPLE PROGRAM #7

CREATE-A-GAME

These four programs will display 3scenes —ahouse

and two rooms. Each scene is stored on disk as apro-

gram file.

10 '"DISPLAY/BAS"

20 '

30 'The ob-Ject of this program

is to show you how you can

40 'access another program from

Your main program. It uses

50 'amain program called

"DISPLAY/BAS" and three graphics

6(3 'pr o gram sca11ed"HOUSE /BAS "»

"FOYER/BAS'S and "STAIRS/BAS"

70 '(Natural 1y thev must be on

dis k b efo r eyoucani- u n this

-APPENDIX C

100

110

120

130

140

150

160

170

180

190

200

210

220

THIS

230

240

250

260

270

280

290

program.

)

106?

170,

202,

234

266,

330,

INKEY*

u^i

CLS

AN* =

IF AN* =

CLS

PRINT 398,

SELECTION

PRINT 3130, "PRESS ANY KEY"

FOR 1=1 TO 40: NEXT I

ON VAL (AN*) GOTO 260,270,280,290

LOAD "HOUSE /BAS ",R

LOAD "FOYER/BAS",R

LOAD "STAIRS/BAS" ,R

END

"HOUSE /BAS"

"SELECTIONS:"

"1) HOUSE"

"2) FOYER"

"3) STAIRS"

"4) END JOB"

"1,2,3, OR 4"

THEN 180

'THEN 250

'TO RETURN FROM

3, 1

PMODE

PCLS

SCREEN 1,0

DRAW "BM66 ,108 "D48 ;R32 ;U48 5L32

DRAW "BM66,68;R132;BM46,96;R132;

BM50, 156;R128"

80 DRAW "BM50,96;D60;BM178,96?D60;

BM206,88;D50"

90 DRAW "BM0, 136 ;R50; BM206, 136;R50"

(46,96)-(66,68>,PSET

<178, 96>-< 198,68) ,PSET

(198, 68) -(206, 88), PSET

(174, 156)~<206, 136), PSET

CIRCLE (92, 130), 5,0

PAINT (0,0), 3,

(0, 149), 1,4

(67,70) ,4,4

(55, 105), 2*

(194, 96), 2,

(82, 128) ,3,4

INKEY*

IF AN* ="" THEN 210

LOAD "DISPLAY/BAS'SR

100

110

120

130

140

150

160

170

180

190

200

210

220

230

LINE

PAINT

AN* =

BL4

BM2

100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250

260

270

280

290

300

310

320

330

340

350

360

370

380

390

400

410

420

430

440

PMODE 3,

SCREEN 1,0

DRAW "BM104,60;D92;R48;U92;L48"

DRAW "BM44,20;R16B;D132;L132;

;L12?BL4?L16;BM44, 102;U82"

DRAW "BM220,60;D100;

44,58?D126"

DRAW "BM42 ,102; D38 ;R8 ;U38 ?L8

DRAW "BM16, 148;D40;R4;U40"

DRAW "BM64, 14B;D40;L4;U40"

DRAW "BM80 ,124; D40 ;L4 ?U36

CIRCLE (144, 108),

(238, 117),

(45, 140), 15,4, .3,0, .7

(45,140), 15,4, .3, .95,

(53, 136),

(0, 192) -< 16, 176), PSET

(20, 172)-(44, 152), PSET

(256, 192)-(212, 152), PSET

(28, 8), 3,

(0,0) -(44, 20), PSET

(256, )-(212, 20 ),PSET

(220,60)-(244,59)

(16, 148>-(44, 124)

(16, 148)-(64, 148)

(64, 148)-(80, 124)

(80, 124)-(52, 124)

(10, 10), 3,

(60, 32), 3,

(240, 20), 3,

CIRCLE

LINE

PAINT

LINE

PAINT

PAINT-

PAINT

CIRCLE

PSET

(128 ,64 ),2,

(228, 70), 2,

(62, 156) ,4,4

(78, 150), 4,

(18, 156), 4,

(68, 128), 1,4

(128, 156), 2,

(40, 140), 4,

(48, 120), 2,

(46, 98), 5, 2,;

AN* =INKEY*

IFAN* =""THEN 420

LOAD "DISPLAY/BAS'SR

"STAIRS/BAS"

10 '

20 '

30 PCLS

"FOYER/BAS"

PCLS

PMODE 3,

SCREEN 1,0

DRAW "BM60,20;R140;D120;L40?U32;

L4;D52;R4;U20;BM160, 160-L128;U150"

70 DRAW "BM4,62;D130;BM28, 166?U102;

BM144, 148; R12"

80 DRAW "BM40,72;D24;R36;U24;L36;

APPENDIX C-

BM44,76;D16;R2S;U16;L28"

90 LINE (32, 12)-(92, 12),PSET

100 LINE (92, 12)~(100,20),PSET

11.0 LINE <0,0)-(60,20),PSET

120 LINE <200,20)-<255,0>,PSET

130 LINE (200, 140) -(255? 192), PSET

140 LINE (0, 192>-(32, 160),PSET

150 LINE <4,62>-<28,64),PSET

160 PAINT (120,4), 2,

170 PAINT (20, 20), 2,

180 PAINT (230, 20), 2,

190 PAINT (120, 40), 2,

200 PAINT (60, 16), 3,

210 PAINT (20, 64), 3,

220 PAINT (158, 124) ,4,4

230 PAINT (42, 74), 4,

240 LINE (28,8)-( 144, 148), PSFT

250 LINE (64, 12) --(156, 122),PSET

260 LINE (68, 12)-(156, 116),PSET

270 DRAW "BM144, 148;U38"

280 FOR 1=0 TO 9

290 DRAW "BM~8,28?U38"

300 NEXT I

310 DRAW "BM56,40;U28?BM48,31 i111 85

BM40,22"U10"

320 PAINT (56, 84), 2,

330 CIRCLE(56,86),10,3, .4,0, .5

340 LINE (51,86)-(63,86) ,PSET

350 DRAW "BM56,84;L4;E7?D8"

360 FOR 1=1 TO 32

370 CIRCLE (120, 176), 1*2, 1/4, .25

380 NEXT I

382 DRAW "BM232 ,176 5U100 ;R2 ;D100

383 CIRCLE (232, 180) ,15 ,4, 1, . 5,

384 CIRCLE (232, 178) ,6, 4, 2, .55 ,.

385 CIRCLE (232, 80) ,15 ,4, 1,0, .

386 CIRCLE (232, 82) ,6, 4, 2, .1, . 55

390 AN* =INKEY*

400 IF AN* ="" THEN 390

410 LOAD "DISPLAY/BAS'SR

SAMPLE PROGRAM #8

BUDGETING

This organizes your finances and prints out ajournal on

your printer. You need aline printer with aline length

of at least 80 characters to run it.

10 'Budget program

20 '

30 'The object of this program

is to build three direct access

40 'files, one alisting of a

balanced budget, another, alisting

50 'of transactions, and the

third, alisting of the updated

60 'budget. The program allows

for carryover from the previous

70 'period's budget. AJournal

can be printed out giving alist

80 'of the budget ,expenses, and

balances. (NOTE: As written,

90 'this program requires aprinter

for outputting the Journal.

100 'However, with slight modifi-

cation, it could be used without

110 'aprinter.

)

120 '

130 '

140 'Main module of program

150 '

160 CLS

170 PRINT 3106, "SELECTIONS:"

180 PRINT 3165, "1) BUILD BUDGET"

190 PRINT a197, "2) UPDATE AN

ACCOUNT"

200 PRINT 3229, "3) PRINT OUT A

JOURNAL"

210 PRINT 3261, "4) END JOB"

220 PRINT 3329, "1,2,3, OR 4?"

230 AN*= INKEY*

240 IF AN*="" THEN 230

250 ON VAL(AN*) GOSUB 360,950,

1450, 1970

260 GOTO 160

270 '

280 'This subroutine builds the

budget file (cal led

290 'BUDGET.ORG), and builds or

updates the file BUDGET. UPD

300 'It allows you to input the

start date of the budget

310 'and the total amount yolt

have to divide up to accounts.

320 'Tentative amounts are entered

for each account and a

330 'running balance is kept to

advise you of the amount

340 'left in Your total budget.

350 '

360 OPEN "D" ,#1 ,"BUDGET/ORG" ,

370 OPEN "D",#2, "BUDGET/UPD" ,5

380 FIELD #1,5 AS OAMT*

390 FIELD #2,5 AS UPDAMT*

400 GOSUB 1810

410 IF L0F(2) =THEN 470

420 FOR 1=1 TO 9

430 GET #2,

440 AMT(I) =CVN( UPDAMT*)

.APPENDIX C

450 PTOT =PTOT +AMT(I)

460 NEXT I

470 CLS

480 PRINT a130. "DATE(MM/DD/YY) :"

490 PRINT 3162, "PROJECTED INCOME

FROM:"

500 PRINT a196, "SALARY:"

510 PRINT a228, "OTHER:"

520 PRINT a96

530 INPUT "DATE(MM/DD/YY> :";DATE*

540 PRINT 3162, "PROJECTED INCOME

FROM:"

550 INPUT "SALARY: ";SAL

560 INPUT "OTHER:" ;OTHER

570 BTOT =SAL +OTHER

580 CLS

600 PRINT 39, "CURRENT BUDGET"

610 PRINT "ACCT# DESCRIPTION

BALANCE"

620 SUMBUD =

630 FOR 1=1 TO 9

640 PRINT USING "####7. 7.

"/. 7.####. ##-" ;ACNO< I) ;

SPACE* ;DESC* (I )?AMT (I

)

650 SUMBUD =SUMBUD +AMT(I)

660 NEXT I

670 PRINT 386, USING "*####.##-"

?AMT(1)

680 PRINT 3419, USING

"7. 7.**###.##";

"REMAINING MONEY: "5BTOT -(SUMBUD

-PTOT)

690 PRINT a451, "ENTER ACCT# OF

ITEM TO BE"

700 INPUT "CHANGED (000 TO

QUIT)" ;AN

710 IF AN =THEN 790

720 CLS

730 N=AN /100

740 PRINT a105,ACNO(N)

750 PRINT 3138,DESC*(N>

760 PRINT a170, "*" ;AMT(N)

770 PRINT: INPUT »NEW

AMOUNT" ;AMT(N)

780 GO TO 580

790 DATE =VAL( LEFT* (DATES, 2) +

M:i.'D*(DATE*,4,2) +RIGHT* (DATE*, 2) )

800 LSET OAMT* =MKN*(DATE)

810 PUT #1,

820 FOR 1=1 TO 9

8;<0 LSET OAMT* =MKN* (AMT (I) )

840 LSET UPDAMT* =MKN*(AMT(I))

850 PUT #1,1+1

860 PUT #2,

8/0 NEXT I

880 CLOSE

890 RETURN

900 '

910 'This subroutine builds a

transaction file called TFILE.DAT

920 'which contains anv updates

to the budget, and updates the

930 'file BUDGET. UPD .

940 '

950 OPEN "D",#l, "BUDGET/UPD-,5

960 OPEN "D",#2,"TFILE/DAT",36

970 FIELD #1,5 AS UPDAMT*

980 FIELD #2,3 AS ACN0*,8 AS DATE*,

20 AS DESC*,5 AS TAMT*

990 FOR 1=1 TO 9

1000 GET #1,

1010 AMT(I) =CVN(UPDAMT*>

1020 NEXT I

1030 GOSUB 1810

1040 CLS

1050 SUMBUD =

1060 PRINT a9, "CURRENT BUDGET"

1070 PRINT "ACCT# DESCRIPTION

BALANCE"

1080 FOR 1=1 TO 9

1090 PRINT USING "####7. 7.

7.####.##-" ;ACNO(I) ;

SPACES* ;DESC* (I);AMT (I

)

1100 SUMBUD =SUMBUD +AMT(I)

11.1.0 NEXT I

1120 PRINT 386, USING

"*####.##-" 5AMT(1)

1130 PRINT a419, USING "7. '/.

**### .## ";»TOTAL BALANCE :";SUMBUD

1140 PRINT a451, "ENTER ACCT# OF

ITEM TO BE

1150 INPUT "UPDATED (000 TO QUIT)"; AN

1160 IF AN =THEN 1350

1170 CLS

1180 N=AN /100

1190 PRINT a95, AN

1200 PRINT DESC*(N)

1210 PRINT USING "7. %

**###.##" ;» CURRENT BALANCE" ;AMT (N)"

1220 PRINT: INPUT "DATE (MM/DD/YY) ";DT*

1230 PRINT "DESCRIPTION OF

TRANSACTION:"

1240 INPUT DS*

1250 PRINT "AMOUNT OF TRANSACTION:"

1260 PRINT "(NEGATIVE NUMBER FOR A

CREDIT)"

1270 INPUT TRANS

1280 AMT(N) =AMT(N) -TRANS

1290 LSET ACNO* =RIGHT* (STR* (AN) ,3)

APPENDIX C.

1300

1310

1320

1330

1340

1350

1360

1370

1380

1390

1400

1410

1420

DT*

DS*

LBET DATE* =

LSET DESC* =

LBET TAMT* =MKN* <TRANS)

PUT #2,L0F<2)+1

GOTO 1040

FOR 1=1 TO 9

LSET UPDAMT* =MKN*(AMT(

PUT #1,1

NEXT I

RETURN

I) )

This prints o u

subrout ine

aJour-nal listing the

1430 'budget ,transact icms, and

balances.

1440 '

1450 OPEN "D",#l, "BUDGET/0RG",5

1460 FIELD #1,5 AS AMT*

1470 OPEN "D",#2, "TFILE/DAT",36

1480 FIELD #2,3 AS TACNO*, 8AS

TDATE*,20 AS TRDESC*,5 AS TMT*

1490 GOSUB 1810

1500 CLS

1510 PRINT 3172, "PRINTING"

1520 Get #1, I

1530 DATE* =STR*(CVN(AMT*)

)

1540 IF LEN(DATE*) <6THEN DATE*

=" " +DATE*

1550 DATE* =LEFT* (DATE*, 2) +

"/" +MID*(DATE*,3,2) +"/"+

RIGHT* (DATE*, 2)

1560 PRINT #-2, TAB (30) "BUDGET FOR

THE PERIOD"

1570 PRINT

"STARTING

1580 PRINT

1590 PRINT

1600 PRINT OR"

#-2, TAB (31)

";DATE*

#-2: PRINT #-2

#-2 ,TAB (28 )"ACCOUNT

#-2, TAB (10)

"ACCOUNT" ?TAB(27) "TRANSACTION"

1610 PRINT #-2, TAB (10) "NUMBER"

TAB (14)" DATE "?TAB (27 )"DESCR IPT ION

TAB (47 )"TRANSACTION" ;TAB (61

)

"BALANCE"

1620 FOR 1=2 TO LOF(l)

1630 GET #1,

1640 PRINT #-2

1650 PRINT #-2,TAB(12)ACN0(I-l>

;

TAB (17) DATE* ;TAB (27 )DESC* (I-1)

;

TAB(61)CVN(AMT*)

1660 BAL=CVN(AMT*)

1670 FOR J=l TO L0F(2)

1680 GET #2,

1690 IFACNO (I-1)<>VAL (TACNO*

)

THEN 1730

1700 BAL=BAL -CVN(TMT*>

1710 IF CVN(TMT*) <,0 THEN CR*="CR"

ELSE CR*=""

1720 PRINT #-2,TAB(17)TDATE*?TAB(27)

TRDESC* 5TAB (47 )ABS (CVN (TMT* ))!CR*

?TAB (61 )BAL

1730 NEXT J

1740 NEXT I

1750 CLOSE

1760 RETURN

1770 '

1780 'This subroutine sets the

values of the account numbers,

1790 'ACNO(I), and account

de scriPt io n s ,DESC* (I)

1800 '

FOR 1=1 TO 9

ACNO(I) =I*100

NEXT I

1810

1820

1830

1840 DESC*( 1)

1850 DESC*<2)

1860 DESC*(3)

1870 DESC* (4)

1880 DESC*(5)

1890 DESC*(6)

1900 DESC* (7)

1910 DESC*(8)

1920 DESC* (9)

1930 RETURN

1940 '

1950 'This subroutine

the program.

1960 '

1970 END

"FOOD"

"RENT"

"CAR"

"UTILITIES"

"INSURANCE"

"TAXES"

"CLOTHING"

"ENTERTAINMENT"

"MISCELLANEOUS"

terminates

-APPENDIX D

ASCII CHARACTER CODES

These are the ASCII codes for each of the characters on your keyboard. The first column is the character; the second

is the code in decimal notation; and the third converts the code to ahexadecimal Q6-based number).

Chapter 15 shows how to use these codes with CHR$ to produce acharacter.

CHARACTER DECIMAL

CODE HEXADECIMAL

CODE

SPACEBAR

CHARACTER DECIMAL

CODE HEXADECIMAL

CODE

CD is 21 (hex 15); and CD is 93 (hex 5D).

APPENDIX D

LOWER-CASE CODES

These are the ASCII codes for lower-case letters. You can produce these characters by pressing the (SHIFT! and

®keys simultaneously to get into an upper/lower case mode. The lower case letters will appear on your screen in

reversed colors (green with ablack background).

CHARACTER DECIMAL

CODE HEXADECIMAL

CODE

a97 61

b^^H 98

c99 63

e101 65

102 66

g103 67

h104 WflaBfiHHHHflBi

i1105 69

k107 6B

108 kec mm

m109 6D

DECIMAL

CODE HEXADECIMAL

CODE

^APPENDIX E

MEMORYMAP

DECIMAL

0-255

256-1023

1024-1535

1536-2440

2441-top

ofRAM

top ofRAM is

16383 for 16K

systems;

32767 for

32K systems

HEX

0000-00FF

0100-03FF

0400-05FF

0600-0988

0989-top ofRAM

top ofRAM is

3FFF for 16K

systems; 7FFF

for 32K systems

32768-40959

40960-49151

49152-57343

57344-65279

8000-9FFF

A000-BFFF

C000-DFFF

65280-65535

E000-FEFF

FF00-FFFF

CONTENTS

System Direct

Page RAM

Extended Page RAM

Video Text Memory

Additional System

RAM

DESCRIPTION

See Section IV of Getting Started with COLOR

BASIC for detailed information.

This is used exclusively by DISK BASIC.

These Random Access Memory locations are allocated dynamically and

contain the following:

1. Random File Buffer

Area

2. File Control Blocks

(FCBs)

3. Graphics Video

Memory

Total buffer space for random access files, 256

bytes are reserved for this on start-up. This value

can be reset by the FILES statement.

Control data on each user buffer. 843 bytes are

reserved for this on start-up. This value can be

reset by the FILES statement: (number of buffers

set by FILES +1) x281 bytes.

4. BASIC Program

Storage

5. BASIC Variable

Storage

6. Stack

7. String Space

8. User Memory

Extended COLOR

BASIC ROM

COLOR BASIC ROM

COLOR DISK BASIC

ROM

Unused

Space reserved for graphics video pages. 6144

bytes or 4pages are reserved for this on start-up.

This value can be reset by the PCLEAR

statement: number of pages reserved by PCLEAR

X1,536 bytes per page. (Note: All pages must

start at a256-byte page boundary —i.e., a

memory location divisible by 256.)

Space reserved for BASIC Programs and

Variables. 6455* bytes (16K systems) or 22,839*

bytes (32K systems) are reserved for this on start-

up. This value can be reset by different settings of

Random File Buffers, FCBs, Graphics Video

Memory, String Space or User Memory.

Total space for string data. On start-up, 200 bytes

are reserved, but this can be reset by the CLEAR

statement.

Total space for user machine-language routines.

No space is reserved for this on start-up, but this

can be reset by the CLEAR statement.

Read Only Memory

Input/Output

*Ifyou execute aPRINT MEM command, on start-up, you will, get anumber alittle lower than this because of the

overhead necessary to execute this command.

APPENDIX F,

SPECIFICATIONS

Type of disks

Disk Organization

(Formatted disk)

Operating Temperature

Memory Capacity

Unformatted

Soft sector

(I/O sector/track)

Access Time

Track to track

Average

Settling time

Number of indexes

Weight of Disk Drive

Disk Controller

5V4" mini-diskettes

Radio Shack Catalog

Number 26-305

26-405 (package of three)

or 26-406 (package of 10)

Single-sided

Double-density

35 tracks

18 sectors per track

256 data bytes per sector

Directory on track 17

18 to 113 degrees Fahrenheit

10 to 45 degrees Centigrade

218.8 kilobytes per disk

6.2 kilobytes per track

179.1 kilobytes per disk

5.1 kilobytes per track

Data transmission speed 250 kilobits per second

5msec.

100 msec.

15 msec.

3.8 kg.

WD1793

APPENDIX G

ERROR MESSAGES

/O Division by zero. The Computer was asked to

divide anumber by 0, which is impossible. You

could also get this error message if you do not

enclose afilename in quotation marks.

AE File Already Exists. You are trying to RENAME

or COPY afile to afilename which Already

Exists.

DS Direct Statement. There is adirect statement in

the data file. This could be caused if you load a

program with no line numbers.

ER Write or Input past End of Record (direct access

only). You are attempting to PUT more data in the

record than it can hold or INPUT more data than

it contains.

AO Attempt to open adata file which is Already

Open.

BR Bad Record Number. You have used an impossible

record number in your PUT or GET line. Either it

is too low (less than 1) or too high (higher than the

maximum number of records the Computer can fit

on the disk). Use adifferent record number in the

PUT or GET line, or assign asmaller record

length in the OPEN line.

BS Bad Subscript. The subscripts in an array are out

of range. Use DIM to dimension the array. For

example, if you have A(12) in your program, with-

out apreceding DIM line which dimensions array

Afor 12 or more elements, you will get this error.

CN Can't continue. If you use the command CONT

and you are at the END of the program, you will

get this error.

DD Attempt to redimension an array. An array can

only be dimensioned once. For example, you can-

not have DIM A(12) and DIM A(50) in the same

program.

DF Disk Full. The Disk you are trying to store your

file on is Full. Use another disk.

DN This is either aDrive Number or Device Number

error.

Drive Number Error. You are using adrive num-

ber higher than 3. You will also get this error if

you do not specify adrive number when using

DSKINI or BACKUP. If you have only one drive

specify drive with these two commands

(DSKINIO or BACKUP 0).

Device Number error. You are using more buffers

than the Computer has reserved. Use FILES to

reserve more. You might also get this error if you

use anonexisting buffer number (such as buffer

#-3) or omit the buffer (such as FIELD 1AS A$

rather than FIELD #1, 1AS A$).

Illegal Function Call. This happens when you use

aparameter (number) with aBASIC word that is

out of range. For example SOUND (260,260) or

CLS(IO) will cause this error. Also RIGHT$(S$,20),

when there are only 10 characters in S$, would

cause it. Other examples are anegative subscript,

such as A( -1), or aUSR call before the address

has been POKEd in.

Bad File Data. This error occurs when you PRINT

data to afile, or INPUT data from the file, using

the wrong type of variable for the corresponding

data. For example, INPUT #1, A, when the data

in the file is astring, causes this error.

Bad File Mode. You have specified the wrong file

mode ("O," "I," or "D") in your OPEN line for what

you are attempting to do. For example, you are

attempting to GET arecord from afile OPENed

for "I" (use "D") or WRITE data to afile OPENed

for "I" (use "O").

Bad File Name. You used an unacceptable format

to name your file.

Field Overflow. The field length is longer than the

record length.

Bad File Structure. There is something wrong

with your disk file. Either the data was written

incorrectly or the directory track on the disk is

bad. See IO for instructions on what to do.

Illegal Direct statement. You can only use INPUT

as aline in the program, not as acommand line.

Input past End of file. Use EOF or LOF to check

to see when you've reached the end of the file.

When you have, CLOSE it.

Input/Output error. The Computer is having trou-

ble inputting or outputting information to the

disk.

APPENDIX G.

(1) Make sure there is adisk inserted properly

in the indicated drive and the drive door is

closed.

(2) If you still get this error, there might be

something wrong with your disk. Try rein-

serting the disk first. Then try using adif-

ferent one or reformatting it. (Remember

that reformatting adisk erases its contents.)

(3) If you still get this error, you probably have

aproblem with the Computer System itself.

Call the Radio Shack Repair Center.

This error could also be caused by input/output

problems with another device, such as the tape

recorder.

String too Long,

characters.

Astring may only be 255

The Computer can't find the disk file you want.

Check the disk's directory to see if the file is there.

If you have more than one disk drive, you might

not have included the appropriate drive number

in the filename. If you are using COPY, KILL, or

RENAME (discussed in the next chapter), you

might have left off the extension.

NEXT without FOR. NEXT is being used without

amatching FOR statement. This error also occurs

when you have the NEXT lines reversed in a

nested loop.

File Not Open. You cannot input or output data to

afile until you have OPENed it.

OB Out of Buffer space. Use FILES to reserve more

space.

OD Out of Data. A READ was executed with insuffi-

cient DATA for it to READ. ADATA statement

may have been left out of the program.

OM Out of Memory. All available memory has been

used or reserved.

OS Out of String Space. There is not enough space in

memory to do your string operations. Use CLEAR

at the beginning of your program to reserve more

string space.

OV Overflow. The number is too large for the Com-

puter to handle.

RG RETURN without GOSUB. ARETURN line is in

your program with no matching GOSUB.

SE Set to non-fielded string. The field in which you

are attempting to LSET or RSET data in has not

yet been FIELDed. Check the FIELD line.

SN Syntax error. This could result from amisspelled

command, incorrect punctuation, open parenthe-

sis, or an illegal character. Type the program line

or command over.

ST String formula too complex. Astring operation

was too complex to handle. Break up the operation

into shorter steps.

TM Type Mismatch. This occurs when you try to

assign numeric data to astring variable (A$ =3)

or string data to anumeric variable (A =

"DATA"). This could also occur if you do not

enclose afilename in quotes.

UL Undefined Line. You have aGOTO, GOSUB, or

other branching line in the program asking the

Computer to go to anonexisting line number.

VF Verification. You will only get the error when you

have the VERIFY command ON and are writing

to adisk. The Computer is informing you that

there is aflaw in what it wrote. See 10 for instruc-

tions on what to do.

WP Write Protected. You are trying to store informa-

tion on adisk which is Write Protected. Either

take the label off the write protect notch or use a

different disk. If your disk is not Write Protected,

then there is an input/output problem. See 10 for

instructions on what to do about this.

.APPENDIX H

DISKBASIC SUMMARY

This is ashort summary on each new DISK BASIC "command." You may also use any of the EXTENDED COLOR

BASIC commands. (See Getting Started with Extended Color BASIC or the Color Computer Quick Reference Card

for acomplete listing.)

The first line gives the format to use in typing the command. The italicized words represent "parameters" —values

which you can specify with the command.

This is the meaning of some of the parameters you may specify:

filename

All information stored on adisk must have afilename. The filename should be in this format:

name/extension:drive number

The name is mandatory. It must have 1to 8characters.

The extension is optional. It can have 1to 3characters.

The drive number is optional. If you do not use it when opening adisk file, the Computer will use drive (or

the drive specified in the DRIVE command).

number

This may be anumber (1, 5.3), anumeric variable (A, BL), anumeric function (ABS(3)), or anumeric operation

(5 +3, A-7).

string

This may be characters ("B," "STRING"), astring variable (A$, BL$), astring function (LEFT$(S$, 5)), or astring

operation ("M" +A$).

data

This may be number or string.

BASIC WORD PAGES

DISCUSSED

BACKUP source drive TO destination drive 13-15

Duplicates the contents of the source drive to the destination drive. If you only

have one drive, specify it as the source drive. The Computer will prompt you to

switch disks as it makes the backup copy. Executing this command will erase

memory.

BACKUP 13 TO 1BACKUP

CLOSE #buffer, . .

26-27

Closes communication to the buffers specified. (See OPEN for buffer numbers).

If you omit the buffer, the Computer will close all open files.

CLOSE «1 CLOSE *1 ,*2

COPY filenamel TO filename2 21

Copies the contents of filenamel to filename2. Each filename must include an

extension. (See format for filenames above.) Executing this command will erase

memory.

COPY "FILE/BAS" TO "NEWFILE/BAS"

COPY "ORG/DAT:0" TO "ORG/DAT: 1"

APPENDIX H.

BASIC WORD DISCUSSED

CVNistring variable) 50

Converts a5-byte coded string (created by MKN$) back to the number it

represents.

x=cvnia$)

DIRdrive number 11

Displays a directory of the disk in the drive number you specify. If you omit the

drive number, the Computer will use drive 0. (Unless you use the DRIVE com-

mand to change this default.) This is atypical directory display:

MYPROG BAS B 3

Y0URPR0G BAS A1

HERDATA DATA 1A 5

USRPROG BIN 2B2

The first column is the name of the file. The second column is its extension. The

third is the file type (0 =BASIC program, 1=BASIC data file, 2=machine lan-

guage file, 3=editor source file). The fourth column is the storage format

(A =ASCII, B=Binary). The fifth column is the file length in granules.

DIR0 DIR

DRIVE drive number 11-15

Changes the drive default to the drive number you specify. If you do not use the

DRIVE command, the Computer will default to drive 0.

DRIVE 1

DSKINIdriue number 8

Formats adisk in the drive number you specify. Executing this command will

erase memory.

DSKINI0 DSKINI1

DSKI$ drive number, track, sector, string variablel, string variable2 61-62

Inputs data from acertain sector within acertain track on the disk in drive

number. The first 128 bytes of data are input into string variablel; the second

128 bytes into string variable2.

DSKI$ 0. 12 .3i M* tN$

DSKO$ drive^number, track, sector, stringl, string2 61-62

Outputs stringMata into the sector, track, and drive number you specify, stringl

is output into the first 128 bytes of the sector; string2 is output into the second

128 bytes. Used improperly, this command could garble the contents of the disk.

DSK0$ 0, 2, 1,"FIRST DATA", "SECOND DATA"

EOF (buffer) 27

Returns aif there is more data to be read in the buffer and a-1if there is no

more data in it. (See OPEN for buffer numbers.)

IF EOFU) =-1 THEN CLOSE «1

FIELD #buffer, field size AS field name, . .

48-49

Organizes the space within adirect access buffer into fields. (See OPEN for

buffer numbers.) You specify the size and name of each field.

FIELD »1» 10 AS A*. 12 AS B$ .5AS C$

.APPENDIX H

BASIC WORD PAGES

DISCUSSED

FILES buffer number, buffer size

Tells the Computer how many buffers to reserve in memory (buffer number),

and the total bytes to reserve for these buffers (buffer size). If you do not use

FILES, the Computer will reserve enough memory space for buffers 1and 2,

and will reserve atotal of 256 bytes for those buffers.

FILES 1.1000 FILES 5

54-55

FREE(drive number)

Returns the number of free granules on the disk in the drive number you

specify.

PRINT FREE(0)

GET #buffer, record number

Gets the next record or the record number you specify, and puts it in the buffer.

(See OPEN for buffer numbers).

GET «1 ,5 GET *2. 3

34-36

INPUT #buffer, variable name, . .

Inputs data from the buffer you specify and assigns each data item in the buffer

to the variable name you specify. (See OPEN for buffer numbers.)

INPUT «1. A$. B$

26-28

KILL filename

Deletes the filename you specify from the disk directory. (See the format for file-

names above.) You must include the extension with the filename.

KILL "FILE/BAS" "KILL FILE/DAT:1"

LINE INPUT #buffer, data

Inputs aline (all the data up to the (ENTER) character) from the buffer you specify.

(See OPEN for buffer numbers).

LINE INPUT «1 ,X$

42-43

LOAD filename, R

Loads the BASIC program file you specify from adisk into memory. By includ-

ing R, the Computer will RUN the program immediately after loading it. If

your filename does not have an extension, the Computer assumes it is BAS. (See

the format for filenames above.) Executing this command will erase memory.

LOAD "PROGRAM", RLOAD "ACCTS/BAS: 1"

LOADM filename, offset address

Loads amachine-language program file from disk. You can specify an offset

address to add to the program's loading address. If your filename does not have

an extension, the Computer assumes it is BIN. (See the format for filenames

above.)

LOADM "PROG/BIN. 3522

LOC(buffer)

Returns the current record number of the buffer you specify. (See OPEN for

buffer numbers.)

PRINT L0C(1)

APPENDIX H.

basic word magnSro

LOF(buffer) 37

Returns the highest numbered record of the buffer you specify. (See OPEN for

buffer numbers.)

FOR R=1TO L0F(1)

LSET field name =data 48-50

Left justifies the data within the field name you specify. If the data is larger

than the field, the RIGHT characters will be truncated (chopped off).

LSET A$ ="BANANAS" LSET B$ =T$

MERGE filename, R53-54

Loads aprogram file from disk and merges it with the existing program in

memory. If you include R, the Computer will immediately run the program

after merging it. (See the format for filenames above.) The disk program file

cannot be MERGEd unless it was SAVEd with the A(ASCII) option.

MERGE "SUB/BAS" MERGE "NEW". R

MKN$(number) 50

Converts anumber to a5-byte coded string, for storage in aformatted disk file.

LSET B$ =MKN*(53B78310)

OPEN "mode" #buffer, filename, record length 26-28,

Opens aplace in memory called abuffer which will communicate data to and 29-31,

from acertain device. The buffers and the devices they communicate with are: 33-38

—screen or printer (it is not necessary to open this buffer)

-1—tape recorder

-2 —printer

1-15 —disk drive

The communication modes you can use are:

I—inputting data from asequential access file

O—Outputting data to asequential access file

D—Inputting or outputting data to adirect access file

The filename you use should be in the format defined above. If you do not give

filename an extension, the Computer will give it the extension DAT.

If you are opening communication to adirect access file, you can also specify

the record length. If you don't, the record length will be 256 bytes.

OPEN "D" f«1 ."FILE" ,15

OPEN "I" »*2 "CHGE/DAT"

PRINT #buffer, data list 27-28

PRINTs the data to the buffer. (See OPEN for buffer numbers.) You may use a

comma or asemi-colon to separate each item in the data list.

PRINT «1 ."DATA"

PRINT #buffer, USING format; data list 45-46

Prints data to the buffer using the format you specify. The format is astring

which can either specify anumerical or string format,

numerical formats may consist of any of the following:

#sets the field of anumber

formats adecimal point

.APPENDIX H

BASIC WORD DlIcufsED

,formats acomma every third number

** fills leading spaces with asterisks

$places $ahead of number

$$ floating dollar sign

+in first position, causes sign to be printed before number; in last

position causes sign to be printed after the number

-•-•"• prints number in exponential notation

-prints a-minus sign after negative numbers

PRINT USING *1 ."*«.*"; 53.76

PRINT USING #2. "#*$#.«*-"! -3.G78

string formats may consist of either:

%%fields the length of astring.

!!prints the first character of the string

PRINT USING *1 ."!"i "WHITE"

PRINT USING *1. "X Z"i "YELLOW"

See Going Ahead With Extended Color BASIC for more information on the

formats.

PUT #buffer, record number 34

Assigns arecord number to the data in the buffer. If you do not specify arecord

number, the Computer will assign it to the current record. (See OPEN for buffer

numbers.)

PUT *2. 3PUT «1 >H

RENAME old filename TO new filename 19-20

Renames afile on disk to anew filename. You must specify the extension ofboth

filenames.

RENAME "MFILE/DAT:1" TO "BFILE/DAT: 1

RSET field name =data

Right justifies the data within the field name you specify. If the data is larger

than the field, the RIGHT characters will be truncated (the same as with

LSET).

RSET M$ ="SOAP"

RUN filename, R9

Loads filename from disk and runs it. If Ris included, all open files will remain

open. (See the format for filenames above.)

RUN "FILE' RUN "PROG/BAS" ,R

SAVE filename, A8

Saves filename on disk. If you do not give filename an extension, the Computer

will give it the extension BAS. By using the Aoption, your program will be

saved in ASCII format. (See the format for filenames above.)

SAVE "PROG/BAS" SAVE "TEST:1" ,A

SAVEM filename, first address, last address, execution address 61

Saves filename —amachine language program beginning at first address (in

memory) and ending at last address. You also specify the address in which it

will be executed. If you do not give filename an extension, the Computer will

give it the extension BIN. (See the format for filenames above.)

SAVEM "FILE/BIN: 1" ,&H5200 ,&H5800 .&H5300

APPENDIX H,

PAPFS

BASIC WORD DISCUSSED

UNLOAD drive number 13

Closes any open files in the drive number you specify. If you don't specify adrive

number the Computer will use drive (or the drive number you specified with

DRIVE).

UNLOAD UNLOAD

VERIFY ON 15

VERIFY OFF

Turns the verify function ON or OFF. When VERIFY is ON, the Computer will

verify all disk writes.

WRITE #buffer, data list 25"26'

Writes the data to the buffer you specify. (See OPEN for buffer numbers.) Use 34-35

acomma to separate each item in the data list.

WRITE *1 >A$ .B$i C

JNDEX

SUBJECT PAGES

ASCII 11,54, 59, 78, 79

BACKUP 13, 14, 84

Binary 11,54

Bits 7, 57

Buffer 26, 29, 54, 55, 84

Bytes 7, 41 ,57, 58, 59

CLOSE 26, 27, 34, 84

Connections 1,2

COPY 21,84

CRC 58

CVN 50, 85

DCBPT 60

DCDRV 60

DCODC 60

DCSEC 60

DCSTA 60

DCTRK 60

DECIMAL CODE 78, 79

Destination Disk 14

Direct Access File 33-38, 47, 48

DIR 11,85

Directory 11,25, 58

Directory Entries 58

Direct Input 48

Disk

Care of disk 13-17

Formatting 7-8

Inserting 3

Disk Drive 2, 8

Disk System 1,57

Drive Number 11,85

DSKCON 60, 60

DSKINIO 8,14,85

DSKI$ 61,62

DSKO$ 61 ,62, 85

EOF 27, 45, 85

Error Messages 16, 82, 83

Field 86

FIELDED INPUT 49

File Allocation Table 59

Files 8, 25, 54, 55, 58, 86

Filename 10, 59, 84

Filename Extension 59, 84

File number 84

FORMAT 7, 8, 47

FREE 86

GET 34, 35, 36, 86

Granule 58, 59

Hexadecimal 57

SUBJECT PAGES

INPUT 26, 27, 34, 36, 37, 42,

43,61,86

Interface 2

KILL 20, 86

LINE INPUT 42, 43, 86

LIST 9

LOAD 9, 86

LOADM 61 ,87

LOC 87

LOF 37, 87

Logical Sector 59, 60

LSET 48, 49, 50, 87

Machine-Language 57, 60, 61

Memory 9

MERGE 53, 54, 87

MKN$ 50, 87

Multi-Disk Drives 20

NEW 9

Numerical Formats 88

OPEN 26, 27, 34, 87

OUTPUT 26, 27, 61

Physical Sector 59, 60

PRINT 19, 27, 43, 44, 45, 48, 88

PRINT FREE 20

PRINT USING 45, 88

PUT 34, 35, 36, 88

Records 33, 34, 36, 37, 55

RENAME 19, 88

RESET 15

RMB 60

RSET 89

RUN 9,89

Salvage aDisk 15

SAVE 8,19,89

SAVEM 61,89

Sector 7, 57, 58

Sequential Access File 29-31

SKIP FACTOR 59

Source Disk ,.14

Specifications 81

Start-up 2-3

Storing on Disk

ABASIC Program 8

AData File 23-39

AMachine-Language Program 61

Machine-Language Routine 60

String 84

String Format 88

System Controls 57

INDEX

SUBJECT PAGES

Technical Information 57-62

Tracks 57, 58

UNLOAD 13,89

VERIFYOFF 15, 89

VERIFYON 15, 89

WRITE 25, 34, 35, 37, 42, 89

WRITE PROTECT 15

SERVICE POLICY

Radio Shack's nationwide network of service facilities provides quick, conve-

nient, and reliable repair services for all of its computer products, in most

instances. Warranty service will be performed in accordance with Radio

Shack's Limited Warranty. Non-warranty service will be provided at reasonable

parts and labor costs.

Because of the sensitivity of computer equipment, and the problems which can

result from improper servicing, the following limitations also apply to the

services offered by Radio Shack:

If any of the warranty seals on any Radio Shack computer products are

broken, Radio Shack reserves the right to refuse to service the equipment or

to void any remaining warranty on the equipment.

2. If any Radio Shack computer equipment has been modified so that it is not

within manufacturer's specifications, including, but not limited to, the in-

stallation of any non-Radio Shack parts, components, or replacement

boards, then Radio Shack reserves the right to refuse to service the equip-

ment, void any remaining warranty, remove and replace any non-Radio

Shack part found in the equipment, and perform whatever modifications are

necessary to return the equipment to original factory manufacturer's speci-

fications.

3. The cost for the labor and parts required to return the Radio Shack com-

puter equipment to original manufacturer's specifications will be charged to

the customer in addition to the normal repair charge.

RADIO SHACK, ADIVISION OF TANDY CORPORATION

U.S.A.

FORT WORTH, TEXAS 76182

CANADA

BARRIE, ONTARIO, L4M4W5

TANDY CORPORATION

AUSTRAUA BELGIUM UNITED KINGDOM

91 KURRAJONG ROAD PARC INDUSTRIE!. NANINNE BILSTON ROAD, WEDNESBURY

MOUNT DRUITT, N.S.W. 2770 5140 NANINNE WEST MIDLANDS WS1B 7JN

874947OBC0 PRINTED IN U.S.A.

Radio Shack Hardware Manual Color Computer Disk System Owners 1981 Tandy Text

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