Radio Shack Hardware Manual SA800 801 Diskette Drive OEM 1977 Shugart Text

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TABLE OF CONTENTS
1

Introduction
1 .1

General Description
Specification

Summary

.2.1

.2.2 Functional Specifications

.2.3 Physical Specifications

.2.4 Reliability Specifications

Performance Specifications

2.0 Functional Characteristics

General Operation
2.2 Read/Write and Control Electronics
2.1

2.3 Drive

5
5

2.4

2.5

Mechanism
Positioning Mechanism
Read/Write Head

2.6 Recording

5
6

Format

Model Differences

6
6

3.0 Functional Operations

Power Sequencing

2.7 Optional Features

2.8

3.1

3.2 Drive Selection

3.3 Track Accessing

7
7

Step Out
3.3.2 Step In
3.4 Read Operation
3.5 Write Operation
3.6 Sequence of Events
3.3.1

4.0 Electrical Interface
4.1 Signal Interface

4.1.1 Input Lines
4.1.1 Input Line
4.1

4.1

Termination

Drive Select 1-4
Direction Select

4. 1.1.

Step

4.1

Write Gate

4.1.1.6 Write Data
4.1.1.7
4.1

4.1 .2

Head Load (Alternate Input).
Use (Alternate Input)

.8 In

Output Lines
Track 00

4.1 .2.1

4.1.2.2 Index
4.1 .2.3

Sector (SA801 only)

4.1 .2.4

Ready
Read Data
Sep Data
Sep Clock

4.1 .2.5
4.1 .2.6
4.1 .2.7

Write Protect (Optional on SA800)
4.1 .2.9 Disk Change (Alternate Output)

4.1 .2.8

4.1.3 Alternate I/O Pins

Power Interface
AC Power
4.2.2 DC Power

4.2

4.2.1

7
7

9
13
13
13
15
15
15
15
15
16
16
16
16
16
16
17
1

18
18
18
18
19

5.0 Physical Interface

J1/P1 Connector

5.2 J5/P5 Connector

22
22
23
23
23
23
23
25
25
27
30

5.1

5.3 J4/P4 Connector

6.0 Drive Physical Specifications

Dimensions

6.1 Drive

6.2 Mounting

Recommendations

6.2.1 Vertical

Mounting

6.2.3 Upright Mounting
6.3 Chassis Slide
6.4 Decorative
7.0

Customer
7.1

Face Plate

Installable Options

Drive Select

One

to Eight Drives

7.2 Select Drive Without Loading
7.3 Select Drive

Head

or Enabling Stepper Motor

and Enable Stepper Without Loading Head

Load Head Without Selecting Drive or Enabling Stepper
7.5 Radial Ready
7.4

7.6 Radial Index/Sector
7.7 Eight, 16,

7.8

Or 32 Sectors

Use Alternate

Input (Activity

7.9 Write Protect Optional

7.10 Disk

Change

(Alternate Output)

8.0 Operation Procedures
8.1 Diskette

Loading and Handling

8.2 Write Protecting a Diskette

9.0 Error Detection and Correction
9.1

Write Error

9.2

Read

LED)

Use

Error

Appendix A - Models and Features

32
32
33
34
35
36
36
37
38
38
39
40
40
40
41

LIST

OF ILLUSTRATIONS

Figure 1.SA800/801 Diskette Storage Drive
2.
3.
4.
5.

6.
7.

8.
9.

SA800/801 Functional Diagram
Track Access Timing
Read Initiate Timing
Read Signal Timing
Write Initiate Timing
Write Data Timing
General Control and Data Timing Requirements
Interface Connections

10. Interface Signal Driver/Receiver
1 1
1

8
8
9
10
10
11

14
16
16
17

Index Timing
Sector Timing

13. J1

Connector Dimensions

J5 Connector

.22

J4 Connector

22
22
23
24
25
26
28
29
30

Connectors- Physical Location Diagram
1 7. Head Load Actuator Mounting Prerequisites
18. SA800/801 Diskette Storage Drive Dimensions
19. Slide Mounting Dimensions
20. SA800/801 R Dimensions
21 Component Locations Standard PCB
16. Interface

22.

Component Locations

LSI

PCB

23. Drive Select Circuitry
24. Select Drive Without Loading

Head

Circuit

Motor Enable Circuit
26. Load Head Without Selecting Drive or Enabling Stepper Circuit

25. Stepper

27. Radial

Ready Circuit

28. Radial Index/Sector Circuit
29. Sector Timing Relationships
30. Sector Divide Circuit
31. In Use/Activity

LED

Circuit

32. Write Protect Circuit
33. Disk
34. Disk

Change Timing
Change Circuit

35. Loading

SA800/801

36. Diskette Write Protected
37. Write Inhibit

Notch Specifications

32
33
34
34
35
35
36
36
37
37

.38
39
39

Wm
wSK&i

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&i&$

'sf$iag£.*:i

'•

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E=:-^»

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|-.'":gS9E-j

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3»&
S*1Ib!P;

^ : '«BgB»;'.i

;

'W$sBw

|IEB=

;

'nBF
Sfcl

iflHkasl

HHBi

Figure

SA800/801 Diskette Storage Drive

1.0

INTRODUCTION

1.1

General Description

The SA800/801 are enhanced versions of the successful SA900/901 Diskette Storage Drive. The SA800/801
provides the customer with a mature and reliable product, manufactured to the same high standard of excellence as the 900/901, but with additional featuress.

The SA800 Diskette Storage Drive can read and write diskettes
SA900, IBM 3741, 3742 or 3540 and with the IBM System 32.
The SA801 provides the same features as the SA800 with
preclude IBM compatibility.

for

interchange with other SA800's, the

additional flexibility for those requirements which

The SA800/801 Diskette Storage Drives have as standard features: a patented diskette clamping/registration design which eliminates the possibility of damage to the diskette due to misregistration and quarantees
over 30,000 interchanges with each diskette; single and double density capability on the same drive for the
same price; a proprietary ceramic R/W head designed and manufactured by Shugart Associates to provide
media life exceeding 3.5 million passes/track and head life exceeding 15,000 hours; an activity light which
indicates drive in use; and ribbon cable or twisted pair connector for ease of packaging. All of these features
and more are available with the SA800/801
SA800/801 Diskette Storage Drive provide the system designer solutions to his applications requirements
with greater performance and reliability than cassette or cartridge drives, and lower cost with increased
function over I/O and reel-to-reel tape drives.
Applications for the SA800/801 Diskette Storage Drive are key entry systems, point of sale recording
systems, batch terminal data storage microprogram load and error logging, minicomputer program and auxiliary data storage, word processing systems and data storage for small business systems.

The SA100 Diskette, IBM Diskette or equivalent, can be read and written interchangeably between any
SA800and IBM 3741/42, 3747 and 3540. The SA1 01 Diskette can be read or written interchangeably on any
SA801. The SA102 and SA103 are used for double density applications.
improve reliability and serviceability, Shugart is incorporating
Large Scale Integration (LSI) components. These components are:

As a product enhancement,
serves drives a

PCB

into the

SA800

# Control Chip
• Write Channel
• Read Channel
The LSI Control chip performs the following functions:

@
#
®
®
®
®
®
®
®

TRK 00 detector
Index detector
Stepper logic
FM clock/data separator and data window
Sector separator
Write Protect detector
Door open/close detector
Disk change circuit
Ready

signal

The functions listed above are either detected from the drive mechanics or from the Host Interface. As a
proper logic generated by the LSI chip either will be used within the drive electronic circuit to perform stepping, read/write operations or will be fed back to the Host Interface.

result, the

an internal FM data separator is incorporated inside the chip. A jumper option will allow the user to
select the data separator to perform as its predecessor SA800 (jumper FS) or to select the separator to be
compatible with the IBM System 3740 data separator (jumper TS). Thus IBM compatibility will allow direct interfacing with LSI single chip floppy disk controllers.

Also,

1.2 Specification

Summary

Performance Specifications

1.2.1

Capacity
Unformatted
Per Disk
Per Track

Single Density

Double Density

3.2 megabits

6.4 megabits

41.7 kilobits

83.4 kilobits

2.0 megabits

n/a

IBM Format
Per Disk
Per Track
Tranfer Rate
Latency (average)

26.6 kilobits

n/a

250 kilobits/sec.
83 ms

500 kilobits/sec
83 ms

ms
ms
8 ms
35 ms

Access Time

Track to Track

Average

260

260 ms

Settling Time
Head Load Time

ms
ms

1.2.2 Functionai Specifications
IS

360 rpm

Double Density
360 rpm

3200
6400

6400
6400

Single Density
Rotational

Speed

Recording Density
(inside track)

Flux Density

Track Density
Tracks
Physical Sectors

48
77

bpi
fci

tpi

bpi
fci

tpi

SA800
SA801

32/16/8

Index

Encoding Method
Media Requirements

SA800
SA801

MFM/M 2 FM

SA100/IBM Diskette
SA101

SA102/IBM Diskette
SA103

1.2.3 Physical Specifications

Ambient Temperature
Relative Humidity

Maximum Wet Bulb
AC Power Requirements
50/60 Hz ± 0.5 Hz
100/115 VAC Installations

200/230

DC
-5

VAC

Installations

Shipping

Operating

Enviromental Limits

= 40°Fto 115°F(4.4° to46.1°C)
= 20% to 80%
= 78°F (25°C)

= 85 to 127V @ 3A typical
= 70 to 253V @ .18A typical
.

Voltage Requirements
5% 1 .3A typical
5% 0.8A typical

+ 24 VDC ±
+ 5 VDC ±
VDC ±5%.05A

typical (option -7 to -16

VDC)

Mechanical Dimensions (Reference Figures 18 and 20)
= 4 5/8 in. (11.75 cm)
Width
Height
=
9 1/2 in. (24.13 cm)
=
14 1/4 in. (36.20 cm)
Depth
=
13.0 lbs. (5.91 kg)
Weight
Heat Dissipation = 271 BTU/hr. typical (80 Watts)

-40°F to 144°F
1

95%

No Condensation

Storage
-8°F to
1

1 1

7°F

95%

No Condensation

1.2.4 Reliability Specifications

POH
POH

under heavy usage
under typical usage

MTBF:

5000
8000

PM:

Every 5000 POH under heavy usage
Every 15,000 under typical usage

MTTR:

30 minutes

Component

Life:

15,000

Error Rates:

Read Errors:
Hard Read Errors:
Seek Errors:
Soft

Media Life:
Passes Per Track
Insertions:

POH
9

1
1
1

per 10 bits read
12
per 10 bits read
6
per 10 seeks.

x 10
30,000 +

3.5

—

/ .

DC LU
LU CO
LU
DC

>
DC
Q

—

CO
LU

>
<
o
Q_

7
_l
o
LU ^
_l
LU ho
CO o
<
z.
CO
LU
O CO
o
DC
ho
o LU X
LU Q
< n <.

Figure

SA800/801 Functional Diagram

2.0

FUNCTIONAL CHARACTERISTICS

2.1

General Operation

The SA800/801 Diskette Storage Drive consists of read/write and controls electronics, drive mechanism,
read/write head, track positioning mechanism, and the removable diskette. These components perform the
following functions:

and generate control signals.
read/write head to the selected track.
and write data.

Interpret

Move
Read
The

relationship

and interface signals

for the internal functions of the

SA800/801 are shown

Figure

The Head Positioning Actuator positions the read/write head to the desired track on the diskette. The Head
Load Actuator loads the diskette against the read/write head and data may then be recorded or read from
the diskette.
2.2 Read/Write

and Control Electronics

The electronics are packaged on one PCB. The PCB contains:
1

Index Detector Circuits. (Sector/Index for 801).

Head Position Actuator Driver.
Head Load Actuator Driver.

4.
5.

6.
7.

Read/Write Amplifier and Transition Detector.
Data/Clock Separation Circuits.
Write Protect.
Drive Ready Detector Circuit.
Drive Select Circuits.

2.3 Drive

Mechanism

The Diskette drive motor

rotates the spindle at

360 rpm through a

belt-drive system.

50 or 60 Hz power

ac-

commodated by changing the drive pulley and belt. A registration hub, centered on the face of the spindle,
positions the Diskette. A clamp that moves in conjunction with the cartridge guide fixes the Diskette to the
registration hub.

2.4 Positioning

Mechanism

electrical stepping motor (Head Position Actuator) and lead screw positions the read/write head. The
stepping motor rotates the lead screw clockwise or counterclockwise in 1 5° increments. A 1 5° rotation of the
lead screw moves the read/write head one track position. The using system increments the stepping motor
to the desired track.

2.5 Read/Write

Head

The SA800/801 head is a single element ceramic read/write head with straddle erase elements to provide
erased areas between data tracks. Thus normal interchange tolerances between media and drives will not
degrade the signal to noise ratio and insures Diskette interchangeability.

The read/write head is mounted on a carriage which is located on the Head Position Actuator lead screw.
The Diskette is held in a plane perpendicular to the read/write head by a platen located on the base casting.
This precise registration assures perfect compliance with the read/write head. The Diskette is loaded
against the head with a load pad actuated by the head load solenoid.
The read/write head

maximum
wear.

is in

The head surface has been designed to obtain
and from the magnetic surface of the Diskette with minimum head/Diskette

direct contact with the Diskette.

signal transfer to

2.6

Recording Format

of fhe data recorded on the disk is totally a function of the host system, and can be designed
around the users application to best take advantage of the total available bits that can be written on any one

The format
track.

For a detailed discussion of various recording formats, the systems designer should read one of the following:

2.
3.

IBM Compatibility Manual.
Shugart Associates Double Density Design Guide.
SA801/901 Track Formats.

2.7 Optional Features
1

2.
3.

4.
5.

2.8

2 to -1 5 Volt DC to replace -5 Volt DC requirement.
Dust Cover, Not available on "FTseries.
Write Protect for SA800. Standard on SA801
Door Lock. Will lock the door when drive is selected or through alternate I/O pin.
Horizontal mounting with door opening up.
SA800/801 "R" Series. Allows two drives to be horizontally installed in a standard 19" Retma rack. Reference figure 20.

-1

Model Differences

800-1

FM (single dendata separator.
Soft Sectored without data separator.
Mechanics only (No PCB).

Hard Sectored with an

density) data separator

and sector

Soft Sectored with an
sity)

800-2
800-4
801

l^irz]
tOIB
3801

(single

separator.

NOTE:
To convert a 801 to a 800 move the shorting plug from the 801 position
800 cannot be converted to a 801

to the

800

position.

3.0

FUNCTIONAL OPERATIONS

3.1

Power Sequencing

AC and DC power to the SA800/801 can be done in any sequence, however, once AC power has
been applied, a 2 second delay must be introduced before any Read or Write operation is attempted. This
delay is for stabilization of the Diskette rotational speed. Also, after application of DC power, a 90 millisecond delay must be introduced before a Read, Write, or Seek opration or before the control output signals
are valid. After powering on, initial position of the R/W head with respect to data tracks is indeterminant. In
order to assure proper positioning of the R/W head prior to any read/write operation after powering on, a
Step Out operation should be performed until the Track 00 indicator becomes active.
Applying

3.2 Drive Selection

Drive selection occurs

respond

when

a drive's Drive Select line

to input lines or gate output lines.

activated. Only the drive with this line active will

Under normal operation, the Drive Select

line will load

the

R/W

head, apply power to the stepper motor, enable the input lines, activate the output lines and light the Activity
LED on the front of the drive. Optional modes of operation are available. Reference section 7 for these user
installable features.

3.3

Track Accessing

Seeking the R/W head from one track
a.
b.
c.

another

accomplished

Activating Drive Select line.
Selecting desired direction utilizing Direction Select

by:

line.

Write Gate is being inactive.
Pulsing the Step line.

Multiple track accessing is accomplished by repeated pulsing of the Step line until the desired track has
been reached. Each pulse on the Step line will cause the R/W head to move one track either in or out depending on the Direction Select line. Head movement is initiated on the trailing edge of the Step Pulse.
3.3.1

Step Out

line at a plus logic level (2.5V to 5.25V) a pulse on the Step line will cause the R/W
track away from the center of the disk. The pulse(s) applied to the Step line and Direction
Select line must have the timing characterisitics shown in Figure 3.

With the Direction Select

move one

head

3.3.2

Step

With the Direction Select

head

line at

move one

a minus logic level (0V to

track closer to the center of the disk.
timing characterisitics shown in Figure 3.
3.4

.4V),

The

a pulse on the Step

line will

pulse(s) applied to the Step line

cause the R/W
must have the

Read Operation

Reading data from the SA800/801 Diskette Storage drive
a.

Activating Drive Select

Write Gate being inactive.

accomplished

by:

line.

to initiate a read sequence are shown in Figure 4. These timing specificaorder to guarantee that the R/W head position has stabilized prior to reading.

The timing relationships required
tions are required

The timing

of the read signals,

Read Data, Separated Data, and Separated Clock are shown

Figure

DC POWER

DRIVE SELECT

REVERSE

DIRECTION SELECT

FORWARD
J

TRACK 00
OUTPUT SIGNAL

/.s

MIN

fts

MIN

4S
1

fiS

MIN
1

MIN

2H S4

MAX

rr\
4

STEP

fiS

MIN'

•

Figure

MS MIN

Track Access Timing

DC POWER

DRIVE SELECT

STEP

WRITE GATE

VALID READ DATA'
16

MIN

—

50/xS

MIN
35

MS MIN

90 MS MIN*
2

SECONDS

AC AND DC POWER ARE APPLIED AT SAME TIME

Figure

Read

Initiate

Timing

READ DATA

SEP DATA

SEP CLOCK

200 ± 50ns

A= LEADING EDGE OF

MAY BE
MAY BE

BIT

B = LEADING EDGE OF BIT

400 ns
200 ns

Figure

3.5 Write

Read

ITS
ITS

NOMINAL POSITION.
NOMINAL POSITION.

Signal Timing

Operation

Writing data to the SA800/801
a.

FROM
FROM

accomplished

by:

Activating the Drive Select line.
Activating the Write Gate line.
Pulsing the Write Data line with the data to be written.
to initiate a write data sequence are shown in Figure 6. These timing
order to guarantee that the R/W head position has stabilized prior to writing.

The timing relationships required
specifications are required

The timing specifications
3.6

Sequence

for the Write

Data pulses are shown

Figure

of Events

The timing diagram shown

Figure 8

restrictions for proper operation.

shows the necessary sequence

events with associated timing

DC POWER

DRIVE SELECT

STEP

WRITE GATE

—

WRITE DATA

SECONDS

U
IF

AC AND DC POWER ARE APPLIED AT SAME TIME.

Figure

WRITE DATA

Write

Initiate Tinning

r—

LJ
150 ns MIN
1100ns MAX

-&»

4.00,is

± 20ns

2.00/xs

±10ns

Figure

Write Data Timing

2SECMIN
AC POWER

DC POWER

90MSMIN
VALID CONTROL

OUTPUT SIGNALS
500 NS

MAX
"5S"

DRIVE SELECT
0.4/iS

MIN

«fr-

VsMIN
DIRECTION SELECT-

VsMIN
MS MIN

STEP

$&
MS MIN STEPPRONLY

2/*s

MAX

TRACK
OUTPUT SIGNAL

4/xS

MAX

WRITE DATA
90
0.4/tS

MIN

WRITE GATE
^-

MS MIN

MS MIN HEAD LOAD

MS MIN

VALID READ

DATA SIGNAL

MS MIN

MS MIN HEAD LOAD

—»>
m

~5S

nrLT

jj$"

50^s MIN.

NOTE

MS MIN

-g^»

35ms minimum delay must be

introduced after Drive Select to
allow for proper head load settling. If stepper power is to be applied independent of Head Load, than and 8ms minimum delay
must be introduced to allow for stepper settling. See Section 7 on
optional

customer

installable features.

Figure

General Control and Data Timing Requirements

ELECTRICAL INTERFACE

4.0

The interface
1.

Signal

Power

of the

SA800/801 Diskette drive can be divided

The following sections provide the
Reference Figure 9

The
1.

all

each

two categories:

line.

interface connections.

Signal Interface

4.1

for

electrical definition for

into

signal interface consists of

two categories:

Control
Data Transfer

the signal interface are digital in nature and either provide signals to the drive (input), or provide
signals to the host (output), via interface connector P1/J1.

All lines in

4.1.1 Input

Lines

There are ten signal input

lines, eight

are standard and two are user installable options (reference section

7).

The input signals are of two types, those intended to be multiplexed in a multiple drive system and those
which will perform the multiplexing. The input signals to be multiplexed are:
1.

Direction Select

Step

Write Data
Write Gate

The
1.

2.
3.
4.

input signals

Drive
Drive
Drive
Drive

The

which are intended

do the multiplexing

are:

Select 1
Select 2
Select 3
Select 4

input lines

have the following

electrical specifications.

Reference Figure 10

cuit.

= Vin ± 0.0V to + 0.4V
= 40 ma (max)
False = Logical one = Vin + 2.5V to + 5.25V
@lin = ma (open)
Input Impedence = 50 ohms

True

Logical zero

tin

for the

recommended

cir-

FLAT RIBBON OR

TWISTED PAIR

HOST SYSTEM

MAX
DISK CHANGE*
IN

SA800/801

10 FEET

USE'
16

HEAD LOAD'
™i§8Sa|

INDEX
ii-

READY
SECTOR

22
(

801

ONLY

DRIVE SELECT

)

24
26

30
32

DIRECTION SELECT

STEP

WRITE DATA

WRITE GATE

TRACK 00
i"

WRITE PROTECT (OPTIONAL)
\y

READ DATA

SEP CLOCK

-5

DCGND T
<$-

VDC

VDC(-7

to -16

VDC

FFWS

NOTE:

y
y
y
y
y
y
y

15
17

19
21

23
25
27

y
y
y

y
y
y
y
y
y
y
y

35
37

-O

43
-<)

45
47

-0

49
<>

y
y

)

+ 24 VDC
+ 24 V RETURN

AC INPUT
FRAME GROUND
AC INPUT
AC GND

44
46

SEP DATA

•^m

FRAME GND
TWISTED PAIR

Not shown are 5 of the 9 Alternate I/O connections. The connections
2, 4, 6, 8, 10 and 14. Signal return for these lines are on pins 1,
tively. Reference Section 7 for uses of these lines.
pins

for

these lines are on
9 and 13 respec-

3, 5, 7,

*These lines are alternate input/output lines and they are enabled by jumper plugs. Reference
Section 7 for uses of these lines.

Figure

9. Interface

Connections

4.1.1 Input

Line Termination

The SA800/801 has been provided with the capability of terminating the four input lines, which are meant
be multiplexed, by jumpering traces. The four lines and their respective jumpering traces are:
1.

Direction Select

Step

Write Data
Write Gate

Trace
Trace
Trace
Trace

"T3"
"T4"
"T5"
"T6"

In order for the drive to function properly, the last drive on the interface must have these four lines
minated. Termination of these four lines can be accomplished by either of two methods.

1. As shipped from the factory, jumpers are installed on the terminator posts T3, T4, T5, and T6.
these shorting plugs from all drives except the last one on the Interface.

ter-

Remove

External termination may be used provided the terminator is beyond the last drive. Each of the four lines
should be terminated by using a 150 ohm, Va watt resistor, pulled up to +5 VDC.

4.1.1.2 Drive Seiect 1-4

Drive Select
head. In this
output lines.

when activated to a logical zero level, activates the multiplexed I/O lines and loads
mode of operation only the drive with this line active will respond to the input lines and

the R/W
gate the

Four separate input lines, Drive Select 1 Drive Select 2, Drive Select 3, and Drive Select 4, are provided so
up to four drives may be multiplexed together in a system and have separate Drive Select lines. Traces
'DS1 ', 'DS2', 'DS3', and 'DS4' have been provided to select which Drive Select line will activate the interface signals for a unique drive. As shipped from the factory, a shorting plug is installed on 'DS1 '. To select
another Drive Select line, this plug should be moved to the appropriate 'DS' pin. For additional methods of
selecting drives, see section 7.1.
,

that

4.1.1.3 Direction Select

This interface line is a control signal which defines direction of motion the R/W head will take when the Step
line is pulsed. An open circuit or logical one defines the direction as "out" and if a pulse is applied to the
Step line the R/W head will move away from the center of the disk. Conversely, if this input is shorted to
ground or a logical zero level, the direction
of motion is defined as "in" and if a pulse is applied to the step line, the R/W head will move towards the
center of the disk.
4.1.1.4

Step

This interface line is a control signal which causes the
defined by the Direction Select line.

R/W head

move

with the direction of motion as

The access motion is initiated on each logical zero to logical one transition, or the trailing edge of the signal
pulse. Any change in the Direction Select line must be made at least 1 /*s before the trailing edge of the Step
pulse. The read/write head may be prevented from stepping past track 00 by using the "NFO" trace option
on LSI PCB. Refer to Figure 3 for these timings. Note: When going from a reverse seek to a forward seek or
vice versa and additional 8 ms delay must be induced before changing direction.
4.1.1.5 Write

Gate
enables Write Data to be written on the diskette. The inactive
enables the read data logic (Separated Data, Separated Clock, and Read Data) and
Refer to Figure 6 for timings.

The active state

of this signal, or logical zero,

state, or logical one,

stepper

logic.

4.1.1.6 Write

Data

This interface line provides the data to be written on the diskette. Each transition from a logical one level to a
logical zero level, will cause the current through the R/W head to be reversed thereby writing a data bit. This
line is enabled by Write Gate being active. Refer to Figure 7 for timings.
4.1.1.7

Head Load

(Alternate Input)

This customer installable option, when enabled by jumpering Trace 'C and activated to a logical zero level
and the diskette access door is closed, will load the R/W head load against the diskette. Refer to section 7
for

uses and method of

4.1.1.8 In

installation.

Use (Alternate

Input)

This customer installable option, when enabled by jumpering Trace 'D' and activated to a logical zero level
will turn on the Activity LED in the door push button. This signal is an "OR" function with Drive Select. Refer
to section 7.8 for uses and method of installation.

4.1.2

Output Lines

+ 5V

There are six standard and one optional output
lines from the SA800, and eight output lines from
the SA801. Also, there is one Alternate Output
available from the drive. The output signals are
driven with an open collector output stage
capable of sinking a maximum of 40 ma at a

MAX

10 FEET

RIBBON OR
TWISTED PAIR

logical level or true state with a maximum
voltage of 0.4V measured at the driver. When the
line driver is off and the collector current is a

maximum

250 microamperes.

Refer to Figure 10 for the

recommended

circuit.

Figure 10. Interface Signal Driver/Receiver
4.1.2.1

Track 00

of this signal, or a logical zero indicates when the drives R/W head is positioned at track
zero (the outermost track) and the access circuitry is driving current through phase one of the stepper
motor. This signal is at a logical one level, or false state, when the selected drives R/W head is not at track

The active state

00.

4.1.2.2 Index

166.67
provided by the drive
once each revolution of the diskette (166.67 ms)
to indicate the beginning of the track. Normally
this signal is a logical one and makes the transition to the logical zero level for a period of 1.7

This interface signal

(0.4

ms on SA801) once each

timing for this signal

3.33

shown

revolution.

E=lk

1.7

The

(0.4

±
.2

^Kl

MSSA801)

Figure 11.

Figure 11. Index Timing

To correctly detect Index

at the Host Index
should be false at Drive Select time, that is, the
Host should see the transition from false to true
after the drive has been selected.

For additional methods of detecting Index, refer to section

7.6.

—

4.1.2.3

Sector (SA801 only)

This interface signal is provided by the drive 32 times each revolution. Normally, this signal is a logical one
and makes the transition to a logical zero for a period of 0.4 ms each time a sector hole on the Diskette is
detected. Figure 12 shows the timing of this signal and its relationship to the Index pulse.

For additional methods of detecting Sector refer to section 7.7.

5.20

SECTOR

.30

45-

INDEX

2.60

.50

Figure 12. Sector Timing

4.1.2.4

Ready

This interface signal indicates that two index holes have been sensed after properly inserting a diskette and
closing the door, or that two index holes have been sensed following the application of +5V power to the
drive.

For additional methods of using the Ready
4.1.2.5

line, refer to

section 7.5.

Read Data

This interface line provides the "raw data" (clock and data together) as detected by the drive electronics.
Normally, this signal is a logical one level and becomes a logical zero level for the active state. Reference
Figure 5 for the timing and bit shift tolerance within normal media variations.
4.1.2.6

Sep Data

This interface line furnishes the data bits as separated from the "raw data" by use of the internal data
separator. Normally, this signal is a logical one level and becomes a logical zero level for the active state.
Reference Figure 5 for the timing. This line is available on the SA801 and 800 Model 1.
4.1.2.7

Sep Clock

This interface line furnishes the clock bits as separated from the "raw data" by use of the internal data
separator. Normally, this signal is a logical one level and becomes a logical zero level for the active state.
Reference Figure 5 for the timing. This line is available on the SA801 and 800 Model 1 and PCB 25136.

NOTE: True

separation internally inserting up to three missing clock bits to maintain synchronization,
PCB by using trace option "TS".

available on the LSI

4.1.2.8 Write Protect (Optional

on SA800)

provided by the drive to give the user an indication when a Write Protected Diskette is
logical zero level when it is protected. Under normal operation, the drive will inhibit
writing with a protected diskette installed in addition of notifying the interface.
This interface signal
installed.

The

signal

For other methods of using Write Protect, refer to section 7.9.

4.1.2.9 Disk

Change

(Alternate Output)

Reference section 7.10.
4.1.3 Alternate I/O Pins

These interface pins have been provided
methods of use.
4.2

Power

for

use with customer installable options. Refer

to section 7 for

Interface

The SA800/801 Diskette Storage Drive requires both AC and DC power for operation. The AC power
for the spindle drive motor and the DC power is used for the electronics and the stepper motor.
4.2.1

used

AC Power

The AC power to the drive is via the connector P4/J4 located to the rear of the drive and below the AC motor
capacitor. The P4/J4 pin designations are outlined below for standard as well as optional AC power.

P4
PIN

60 Hz
208/230 V

115 V (Standard)

VAC

85-1 27

Frame Gnd

85-127

MAX
CURRENT

0.35

FREQ
TOLERANCE

50 Hz

70-253

VAC

Frame Gnd

VRtn

Amps

70-253 V Rtn

0.23

±0.5 Hz

Amps

110V
85-127

220V

VAC

70-253

VAC

Frame Gnd

85-127 V Rtn

0.35

Amps

70-253 V Rtn

0.23

±0.5 Hz

Amps

DC Power

4.2.2

DC power to the drive is via connector P5/J5 located on non-component side of PCB near the P4 connector.
The three DC voltages and their specifications along with their P5/J5 pin designators, are outlined below.

MAX

P5
PIN

DC VOLTAGE

CURRENT

TOLERANCE

RIPPLE

(p to p)
J

+ 24 VDC

±1.2 VDC

1.7
1

2
3

+ 24 V
-

A Max**
A Typ

Return*

5 V Return

-5 VDC

±0.25 VDC

0.07
0.05

A Max
A Typ

0.10
0.07

A Max
A Typ

1.0

A Max
A Typ

Optional
-7 to -16

VDC

(trace 'L')***

VDC

±0.25 VDC

0.8

V Return

*The +24 VDC power requires a separate
ground return line. It, and all other DC grounds
must be connected together at the power supply. One line from this common DC connection
must go to one common Frame Ground connection

near the power supply.

customer installable option described
sections 7.2 and 7.4 are used, the current requirement for the +24 VDC is a multiple of the
maximum of + 24V current times the number of
drives on the line.
**lf either

-|4

***lf the shorting plug is in the vertical position
the -7 to -1 6 VDC option can be used. If the shorting plug is in the horizontal position, -5 VDC
must be used.

CI3

5.0

PHYSICAL INTERFACE

between the SA800/801 and the host system is via three connectors. The first consignal interface; the second connector, J5, provides the DC power; and the third
the
provides
nector, J1,
conector, J4, provides the AC power and frame ground.

The

electrical interface

This section describes the physical connectors used on the drive and the
used with them. Refer to Figure 16 for connector locations.
5.1

recommended connectors

J1/P1 Connector

is through a 50 pin PCB edge card connector. The dimensions for this connector are shown
The pins are numbered 1 through 50 with the even numbered pins on the component side of the
PCB and the odd numbered pins on the non-component side. Pin 2 is located on the end of the PCB connector closest to the AC motor capacitor and is labeled 2. A key slot is provided between pins 4 and 6 for op-

Connection
in

Figure

tional

to J1

connector keying.

The recommended connectors

for P1 are tabulated

below.

CONTACT

TYPE OF CABLE

MANUFACTURER

CONNECTOR

Twisted Pair, #26
(crimp or solder)

AMP

1-583717-1

58354-3 (solder)

VIKING

3VH25/1JN-5

3415-0001

Twisted

Pair,

Cable

P/N

583616-5 (crimp)

#26

(solder term.)
Flat

P/N

"Scotchflex"

KEY SLOT

.400

.010"

.050"

050"

NOM

.063"

NOM

.100"

2.575

NOM

NOM
.010"

BOARD THICKNESS

Figure 13.

(2X)

Connector Dimensions

.062

.007'

5.2 J5/P5

Connector

©Uo

The DC power connector, J5, is mounted on the
non-component side of the PCB and is located
below the AC motor capacitor. J5 is a 6 pin AMP
Mate-N-Lok connector P/N 1-380999-0. The

recommended mating connector

(P5)

AMP

P/N 1-480270-0 utilizing AMP pins P/N 60619-1.
J5 pins are labeled on the component side of the
PCB with pin 5 located nearest J1/P1. Figure 14
illustrates J5 connector as seen on the drive
PCB from non-component side.
5.3 J4/P4

Figure 14. J5 Connector

Connector

The AC power connector, J4

is mounted on the
capacitor bracket and is located just
below the capacitor. J4 connector is a 3 pin connector AMP P/N 1-480305-0 with pins P/N
60620-1. The recommended mating connector
(P4) is AMP P/N 1-480303-0 or 1-480304-0 both
utilizing pins P/N 60619-1. Figure 15 illustrates
J4 connector as seen from the rear of the drive.

AC motor

AC DRIVE MOTOR CAPACITOR

REAR OF DRIVE

J4AMP

AMP

P/N 1-380999-0

P/N 1-480305-0

AMP
AMP

P/N 1-480303-0
P/N 1-480304-0
P1

CONNECTOR

FLAT CABLE
3M P/N 3415-0001
TWISTED PAIR

AMP

P/N 1-583717-1

VIKING P/N 3VH25/1JN-5

Figure 16. Interface Connectors

Physical Location Diagram

6.0

DRIVE PHYSICAL SPECIFICATIONS

This section describes the mechanical dimensions and mounting recommendations for the SA800/801.

Drive

6.1

Dimensions

Reference Figure 18
6.2

dimensions

of the

SA800/801

Mounting Recommendations

The SA800/801

for

capable

of being

mounted

one

of the following positions:

Vertical-Door opening to the left or right.
Horizontal-Door opening up or down.
Upright-Door opening towards the front or rear.

Mounting

6.2.1 Vertical

The

as shipped from the factory,
without any adjustments.

drive,

right,

ready to be mounted

the vertical position, door opening

Horizontal Mounting

HORIZONTAL

be mounted horizontally with the
door opening down (PCB up), the head load actuator return spring must be repositioned to
compensate for gravity. Reference Figure 1 7 for
the proper spring position on the actuator.

(PCB

the drive

If the door is to open up (PCB down), it must be
specified when ordering. This feature provides a
heavier door opening spring. In addition, the
head load actuator return spring will be reposi-

left

MOUNTING
DOWN)
HORIZONTAL

VERTICAL

MOUNTING

(PCB UP)

UPRIGHT

MOUNTING

tioned to compensate for gravity. Reference
Figure 17 for the proper position for the spring
on the actuator.

Figure 17. Head Load Actuator Mounting Prerequisites

6.2.3 Upright

Mounting

the spring hook attached
If the Drive is to be mounted in the upright position (IBM 3740 fashion),
mechanism must be removed and then attach the eject spring to the place the hook was on.

to the eject

——

00
CO
CD
CD

•—

jo
Cl

=
-co

_CD

^
LU

O
CO
H

-rj

Qo>

O
c

CD
S.

o
_Q
LO
r^
CO

c
O c
"D

CO
CD

o °
E E
CO 2

c
o
o
CD

B
X
CD
_CD

CO
CD

o
E

CM
CD

LO
CM

«3-

LO
CM
LO

CO
o
+1

O o

o
CO
o q

CO
cz
CD

O
o
lo
o
d CD

m
E

CO
cz

III

_l
LU

<
1-

o
o CO
o
+1

>
o

o
CD

00
j

Fsgure 18. SA800/801 Diskette Storage Drive Dimensions

o
o
CD

""7

N
CD
k_
CD

>
o

o o
1

-I—
">

00
LO

•«s(-

1—

O
c
CO

u ^ "1 »

o
h-

6.3

Chassis Slide

Available as an optional accessory is a chassis slide kit P/N 50239. This kit contains two slides, one locking
and one non-locking, and seven screws. Dimensions of the slide are shown in Figure 19. For use on the standard casting only.

n
M»" " l !fflM* *limB ''" ^U^"liM« ".HiMM

MIUJIIIO*

ATTACHED
TOSA800,

Y = TRAVEL

BUM

MMfrfflliMlfahyifff'^^

X= LENGTH ±

-S23-HSJ-

.06'

r—

4--&

.03-

Tr*"

•$*
ffi

.75

75-^»)
«^g~p

^»
-^m-

-G-

LENGTH/TRAVEL VIEW

STANDARD MOUNTING
HOLE SIZE

.177 DIAM.

4.00

8.00

12.00

1.00

3.50

8.50

11.50

12.50

Figure 19. Slide Mounting Dimensions
6.4 Decorative

Face Plate

The SA800/801 may be ordered with one

COLOR

SIZE
4
4
5
5
5
5

5/8
5/8
1/4

1/4

X
X
X
X

of the following decorative face plates:

Tan

10 1/2
10 1/2
10
10

White

Tan
White
Tan

1/4x11
1/4X11

White

"R" Series-4

5/8

8 11/16

Tan

PART NO.
50264
50263
50261

50260
50258
50257
50675

is required to match the system's color scheme, the face plate may be painted. The followbe utilized to avoid potential problems in the painting process.
should
ing information
If

another color

cover is made from GE's LEXAN. Dimensional stability of LEXAN exists from -60°F +250°F. If
the type paint used requires baking, the temperature should not exceed + 250°F, including any hot spots
which can contact the cover.

The

LEXAN

front

a polycarbonate. Any paint to be used should be investigated to insure that
to polycarbonates.

chemicals that are solvents

does not contain

0)
_c

CO
CO

CO
CD

o
CD
CO
CO

CO
CO
CD

c:
"CD

'CD

>
O
o
-^
c

^
X

CO
(J

c
J*:
o

C
E

E
o
o
o
o
o

CO
CO

>
C)
o

O
o

c
o

o
c
LL

>
o
o

C
o
CO

c
o
o

L±_

F
o

E
o

X
"*

X
CM
^
o

LO
CM

SLg

g°

CM
CO

o
CO
1.00

L
r*— 4 50 ± 02"^—**l

54 ± .02

CO LO
CO CM

Figure 20. SA800/801R Dimensions

.01

7.0

CUSTOMER INSTALLABLE OPTIONS

The SA800/801 can be modified by the user to function differently than the standard method as outlined in
sections 3 and 4. These modifications can be implemented by adding or deleting traces and by use of the
Alternate I/O pins. Some traces are capable of being connected by use of a shorting plug, Shugart P/N 1 5648
or AMP P/N 5301 53-2. This section will discuss a few examples of modifications and how to install them. The
examples are:
1

2.
3.

4.
5.

Drive Select one to eight drives.
Select drive without loading head or enabling stepper.
Select drive and enable stepper without loading the head.
Load head without selecting drive or enabling stepper.
Radial Ready.
Radial Index/Sector.

7. Eight, 16,
8. In
9.

Use

or 32 Sector option.

(Activity L.E.D.) optional input.

Write Protect options.

Tabulated below are the trace options with the condition of the trace as
21 shows the location of these traces on the PCB.

shipped from the factory. Figure

CUSTOMER CUT/ADD TRACE OPTIONS
TRACE
DESIGNATOR

SHIPPED FROM FACTORY!

OPEN

DESCRIPTION

Terminations for Multiplexed Inputs
Terminator for Drive Select
Spare Terminator for Radial Head Load

DS1,DS2,DS3,DS4

Drive Select Input Pins

T3,T4,T5,T6
T1

SHORT
Plugged
Plugged

X
X

DS1

Plugged

RR
Rl

R,I,S

HL
DS

WP
NP
8,16,32

Stepper Power From Head Load
Stepper Power From Drive Select
Inhibit Write When Write Protected
Allow Write When Write Protected
8, 16, 32 Sectors (SA801 Only)

2,4,6,8,10,12,14,16,18

Alternate Input-In Use
Nine Alternate I/O Pins

D1,D2,D4,DDS

Customer

A,B,X

Radial Head Load
Alternate Input-Head Load
In Use from Drive Select

DC
NFO

Alternate Output-Disk

True

X
X
X

Radial Ready
Radial Index and Sector
Ready, Index, Sector Alternate Output Pads

Installable

Use from

Decode

Drive Select Option

X
X
X
Plugged

X
Plugged

HD LD

X
X
X
X

Change

Non Force Out

Plugged

Data Separation

—[HIT
-

-*~
i

—

Rl?
Big

- mf
RI6 _

-n

RI5

Hi
ftlS

R5 r

*~"

ca Jumper Plug Installed as Shipped

Test Point

Figure 21. Component Locations Standard PCB

LIO

-riitr
389

H R23

16
+

DL
o
i, i,

HOd-d-d
R.qn

I, I, I,

12 26

„„

o
o
o

DCo

i, i, i,

III

o
11

oo
c oo
oo
R
S oo
D

o fo'ol

i
'

DS1

XJ-

UL
i
9\

,™

DS2 |f ° °
DS3 §gT2
DS4 oo
T3 06
T4 06
T5 66
00
T6

n-n
Rl

D-D

TS
D
D D

NFO

86
izr

258

O D

o o

o801
o
o

T
+

lool [ool lool

DSo
hl!
I

I, I, I, I,

(ool

Tl
3

JJUJU

D-DD B

WPNP9

Figure 22. Component Locations LSI

PCB

7.1 Drive

Select

•

One

to Eight Drives

TRACE
Customer

option allows up to eight
drives to be multiplexed together. This method of
drive selection uses a binary address to select a
installed

ADDRESS

drive.

install this feature on a standard drive, the
following traces should be added or deleted:

Add

a 74L85, 4

P/N
P/N

bit comparator (Motorola
14585, National Semiconductor
74c85) into position 2B on PCB,

(1Aon PCB 25136).

Connect trace 'DDS'.

Insure traces 'DS1' - 'DS4' are plugged.
Jumper traces 'D1\ 'D2\ and 'D4' according to table below for address of each

INTERFACE PIN

drive.

DRIVE

The

four Drive Select lines are to be used for addressing the drives. Pin 26 is used as Drive

Select enable and pins 28 (binary 1), 30 (binary
2), and 32 (binary 4), are the address lines.
Figure 23 illustrates the circuitry. The table
below shows the logical state each line must be
at to select each of the drives.

3
4

Figure 23 illustrates the circuitry.

+ 5VDC

O-

ADDED TRACE
STANDARD TRACE

m DELETED TRACE

DRIVE ADDRESS
2

SHOWN

-DRIVE SELECT 4
-DRIVE SELECT 3

-DRIVE SELECT 2
-DRIVE SELECT

-3-

00
CO

C\J

Q Q Q Q

DDS
-DRIVE SELECT

Figure 23. Drive Select Circuitry
30

Without Loading Head Or Enabling Stepper Motor

7.2 Select Drive

This option would be advantageous to the user who requires a drive to be selected at all times. Normally,
when a drive is selected, its head is loaded and the stepper motor is energized. The advantage of this option
would be that the output control signals could be monitored (with the exception of Track Zero, which requires the stepper to be energized) while the head was unloaded thereby extending the head and media life.
When the system requires the drive to perform a Read, Write, or Seek, the controller would activate the
Head Load line (pin 18) which in turn would load the head and energize the stepper motor. After the Head
Load line is activated, a 35 ms delay must be introduced before Write Gate and Write Data may be applied or

before Read Data

To
1.

install this

valid.

option on a standard drive, the following traces should be added or deleted:

Jumper trace T2\

Remove jumper from

Jumper trace 'C.

trace

'X'.

Figure 24 illustrates the circuitry.

-DRIVE SELECT 4

-DRIVE SELECT 3
-DRIVE SELECT 2
-DRIVE SELECT

ALTERNATE
I/O

+ DRIVE
SELECT

PINS

+ HEAD
LOAD

-DOOR CLOSED $

_ _ STANDARD

m/M

TRACE

DELETED TRACE

ADDED OR JUMPERED TRACE
NOTE:

If the -Head Load line is multiplexed, terminator 'TV
jumper must be removed from each drive except
the last one on the line. Also, the current requirement for the + 24 VDC supply should be a multiple

of the

maximum +24

of drives

on the

volt current

line that

Figure 24. Select Drive Without Loading Head Circuit

times the number

have Head Load

active.

7.3 Select Drive

and Enable Stepper Without Loading Head

This option is useful to the user who wishes to select a drive and perform a seek operation without the head
being loaded or with door open. An example use of this option is that at power on time, an automatic
recalibrate (reverse seek to track zero) operation could be performed with the drive access door open. Normally for a seek to be performed, the door must be closed and the head loaded. Other advantages are those
listed in section 7.2 in addition to being able to monitor Track Zero. When a Read or Write
operation is to be
performed, the head must be loaded (pin 1 8). After the Head Load line is activated, a 35 ms delay must be introduced before Write Gate and Write Data may be applied or before Read Data is valid.

install this

option on a standard drive, the following traces should be

Jumper trace

Remove jumper from
Remove jumper from

4.
5.

Jumper trace
Jumper trace

added

or deleted:

'T2'.

trace 'B'.
trace 'HL'.

'DS'.

Figures 24 and 25 illustrate the circuitry.

Load Head Without Selecting Drive Or Enabling Stepper

7.4

This option is useful in disk to disk copy operations. It allows the user to keep the heads loaded on all drives
thereby eliminating the 35 ms head load time. The head is kept loaded on each drive via an Alternate I/O pin.
Each drive may have its own Head Load line (Radial or Simplexed) or they may share the same line

When the drive is selected, an 8 ms delay must be introduced before a Read or Write operacan be performed. This is to allow the R/W head to settle after the stepper motor is energized. With this
option installed, a drive can only be selected with both Drive Select and Head Load active.
(Multiplexed).
tion

install this

added

or deleted:

Jumper trace T2\

Remove jumper from
Remove jumper from

2.
3.

trace 'A'.
trace 'HL'.

Jumper trace 'DS'.
Jumper trace 'C.

*5.

*lf

option on standard drive, the following traces should be

the -Head Load line
one on the line.

multplexed, terminator 'TV jumper must be removed from each drive except the

last

Figures 25 and 26 illustrate the circuitry.

NOTE: The 8 ms delay may be eliminated by
keeping trace 'DS' open. This would
keep the stepper motor energized at all

+ HEAD LOAD

times.

ment

this is used, the current require-

of the

+ 24 VDC supply must be a
maximum +24 Volt cur-

multiple of the
rent times the

+ DRIVE SELECT

number

of drives

ne.

FROM STEP
COUNTER

Figure 25. Stepper Motor Enable Circuit

> TO STEPPER

on the

-DRIVE SELECT 4 -X
-DRIVE SELECT 3

-* 30

-DRIVE SELECT 2

-H

-DRIVE SELECT

-X

32
4

28
26

III
+ 5VDC
150

ALTERNATE
I/O

+ DRIVE
SELECT

PINS
;=5

-HEAD

4'+5VDC

18-

LOAD^

"^S/S^Sf^
1

+ HEAD

LOAD

-DOOR CLOSED

STANDARD TRACE

WM DELETED TRACE
ADDED OR JUMPERED TRACE
IF

THE -HEAD LOAD LINE IS MULTIPLEXED; TERMINATOR 'T1 JUMPER MUST
REMOVED FROM EACH DRIVE EXCEPT THE LAST ONE ON THE LINE.
'

Figure 26. Load Head Without Selecting Drive or Enabling Stepper Circuit

7.5 Radial

Ready

This option enables the user to monitor the Ready line of each drive on the interface. This can be useful in
detecting when an operator has removed or installed a Diskette in any drive. Normally, the Ready line from a
drive is only available to the interface when it is selected.

install this

option on a standard drive, the following traces should be

Cut trace 'RR'.
Cut trace 'R\
*3. Add a wire from pad

added

or deleted:

*2.

'R' to

one

of the Alternate I/O pins.

*One of the drives on the interface may use pin 22 as its Ready line, therefore, steps 2 and 3 may be
eliminated on this drive. All the other drives on the interface must have their own Ready line, therefore steps
2 and 3 must be incorporated.
Figure 27 illustrates the circuitry.

+ 5V

+ DRIVE SELECT

-READY

+ READY

STANDARD TRACE

WM DELETED

(CUT)TRACE

ADDED TRACE

Figure 27. Radial Ready Circuit

7.6 Radial Index/Sector

This option enables the user to monitor the Index and Sector lines at all times so that the drive may be
selected just prior to the sector that is to be processed. This option can be used to reduce average latency.

install this

option on a standard drive the following traces should be

Cut trace 'Rl\
Cut trace 'I'.
*3. Cut trace 'S'.
*4. Add a wire from trace
*5. Add a wire from trace

added or deleted:

*2.

'I'

'S' to

one of the Alternate I/O pins.
one of the Alternate I/O pins.

*One of the drives on the interface may use pin 20 (-Index) and pin 24 (-Sector) as its Index and Sector lines,
therefore, steps 2-5 may be eliminated for this drive. All other drives on the interface must have their own Index and Sector lines, therefore, steps 2-5 must be incorporated.
Figure 28 illustrates the circuitry.

+ DRIVE SELECT

STANDARD TRACE

ALTERNATE

DELETED (CUT) TRACE
ADDED TRACE

I/O

+ INDEX

©-—^WV"^-i^

-INDEX

+ 5V
-SECTOR

+ SECTOR

Figure 28. Radial Index/Sector Circuit

7.7 Eight, 16,

Or 32 Sectors

factory, is set up to provide 32 Sector pulses per revolution of the Diskette
onto the interface. This option is provided for the user who wishes to have eight or 16 Sectors per revolution.
The logic divides the Sector pulses by two or four. Reference Figure 29 for the timing relationships.

The SA801 as shipped from the
,

install this

option on a standard drive (SA801), the following traces should be

added

or deleted:

'32'.

Cut trace

Connect trace

'16' for

16 Sectors or connect trace

'8'

for eight Sectors.

Figure 30 illustrates the circuitry.

INDEX

5.2

SECTORS
10.4

SECTORS
-20.8

SECTORS

INDICATES BEGINNING OF SECTOR

MS-

RELATIONSHIP TO INDEX

Figure 29. Sector Timing Relationships

+ SECTOR 5—f

+ DRIVE SELECT

-SECTOR

STANDARD TRACE
DELETED (CUT) TRACE
ADDED TRACE
-INDEX

Figure 30. Sector Divide Circuit

7.8 In

Use Alternate Input

(Activity

LED)

This alternate input, when activated to a logical zero level, will turn on the Activity LED mounted in the push
bar on the front panel of the drive. It can be used as an indicator to the operator. Examples of some indications are:

Write protected Diskette is installed.
Drive in which the diskette is to be changed.
The operating system drive.
Drive with a special configuration.

2.
3.
4.

option on standard drive, jumper trace 'D' and active the interface line pin 16.

install this

This signal

"OR"

function with Drive Select or

Head Load. Figure

31 illustrates the circuitry.

ALTERNATE
I/O

PINS

USE

5.1

«AAAr-@ + 5V

-HEAD LOAD J

Figure 31.

7.9 Write Protect Optional

(TO LED)

-DRVSELINT $

Use/Activity

LED

Circuit

Use

As shipped from the

factory, the optional Write Protect feature will internally inhibit writing when a Write Protected Diskette is installed. With this option installed, a Write Protected Diskette will not inhibit writing, but it
will be reported to the interface. This option may be useful in identifying special use Diskettes.

install this

option on a drive with the Write Protect feature, the following traces should be

added

deleted:
1.

^2.

Cut trace 'WP\

Connect trace

'NP'.

Figure 32 illustrates the circuitry.

-WRITE PROTECT

TO INTERFACE

Jj-

-WRITE GATE

TO WRITE CURRENT

J
Figure 32. Write Protect Circuit

7.10 Disk

Change

(Alternate Output)

This customer installable option is enabled by jumpering trace 'DC. It will provide a true signal (logical zero)
onto the interface (pin 1 2) when Drive Select is activated if while deselected the drive has gone from a Ready
Drive Select if the
to a Not Ready (Door Open) condition. This line is reset on the true to false transition of
in Figure 34.
illustrated
The
circuitry
is
Figure
33.
in
illustrated
drive has gone Ready. Timing of this line is

— —

45-

5 S

-DRV SEL

-READY

3!r

-DISKCHG
INTERNAL
ENABLE

*fr

Figure 33. Disk Change Timing

+ 5V
fi.

Q
I

C Q&I

-READY

-DRV SEL 5

"X.

°[^>

H>
Figure 34. Disk Change Circuit

DISKCHG

8.0

OPERATION PROCEDURES

The SA800/801 was designed for ease of operator use to facilitate a wide range of operator oriented applications. The following section is a guide for the handling and error recovery procedures on the diskette and
diskette drive.
8.1

Diskette Loading and Handling

The

diskette is a flexible disk enclosed in a plastic jacket. The interior of the jacket is lined with a wiping
material to clean to disk of foreign material. Figure 35 shows the proper method of loading a diskette in the
SA800/801 Diskette Storage Drive. To load the diskette, depress latch, insert the diskette with the label facing out. (See Figure 35). Move the latch handle to the left to lock diskette on drive spindle. The diskette
can

be loaded or unloaded with

all

power on and

drive spindle rotating.

Figure 35. Loading SA800/80

the drive, the diskette is stored in an envelope. To protect the diskette, the same care
and handling procedures specified for computer magnetic tape apply. These precautionary procedures are

When removed from
as follows:
1.

Return the diskette to

its

storage envelope.

fields and from ferromagnetic materials which might become
magnetized. Strong magnetic fields can distort recorded data on the disk.
Replace storage envelopes when they become worn, cracked or distorted. Envelopes are designed to pro-

tect the disk.
Do not write on the plastic jacket with a lead pencil or ball-point pen.

5.
6.
7.

Keep cartridges away from magnetic

Use a

felt tip

Heat and contamination from a carelessly dropped ash can damage the disk.
Do not expose diskette to heat or sunlight.
Do not touch or attempt to clean the disk surface. Abrasions may cause loss

pen.

of stored data.

8.2 Write Protecting a Diskette

Shugart Media has the capability of being write protected. The write protect feature is selected by the notch
writing is allowed. The notch is closed by
in the media. When the notch is open it is protected; when covered,
The Diskette
placing a tab over the front of the notch, and the tab folded over covering the rear of the notch.
37.
and
Figures
36
Refer
to
tab.
the
can then be write protected by removing

FOLD OVER BACK
OF DISKETTE

)

Figure 36. Diskette Write Protected

.200

.010-

.150

075R ±

Figure 37. Write

Inhibit

.005

-s^C

CZZ)
6.175

Notch Specifications

.005

9.0

ERROR DETECTION AND CORRECTION

9.1

Write Error

an error occurs during a write operation, it will be detected on the next revolution by
doing a read operacommonly called a "write check." To correct the error, another write and write check operation must
be done. If the write operation is not successful after ten attempts have been made, a read
operation should
be attempted on another track to determine if the media or the drive is failing. If the error
still persists the
disk should be considered defective and discarded.
If

tion,

9.2

Read

Error

Most errors that occur
be recovered.

will

Soft errors are usually

caused

2.
3.

be "soft" errors; that

is,

by performing an error recovery procedure the data

by:

Airborne contaminants that pass between the read/write head and the disk. These
comtaminants will
generally be removed by the cartridge self-cleaning wiper.
Random electrical noise which usually lasts for a few ^sec.
Small defects in the written data and/or track not detected during the write operation which
may cause a
soft error during a read.

The following procedures are recommended

recover from the above mentioned soft errors:

Reread the track ten times or

until such time as the data is recovered.
not recovered after using step 1, access the head to the adjacent track
previously moved, then return to the desired track.

Repeat step

will

data

not recovered, the error

not recoverable.

the

same

direction

APPENDIX A MODELS AND FEATURES
-

MODEL DIFFERENCES
FM

Soft Sectored with an

800-2

density) data separator.
Soft Sectored without data

801

800-1

(single

separator.

Hard Sectored with an

density) data separator

and sec-

(single

tor separator.

NOTE:

To convert a 801

to a

800 move

the shorting plug from the 801
position to the 800 position. A 800

cannot be converted

AC VOLTAGE/FREQUENCY CONVERSION

to a 801

MEDIA
DRIVE

MODEL

SINGLE
DENSITY

PRIMARY

PART NUMBERS

DOUBLE

VOLTAGE

DENSITY

AND
FREQUENCY

MOTOR

ASM*

PULLEY

BELT

115VAC,60HZ

50443

50358

50356

115VAC.50HZ

50443

50357

50355

230VAC.60HZ

50444

50358

50356

230VAC50HZ

50444

50357

50355

800-1

SA1 00

SA102

800-2

SA100

SA102

801

SA101

SA103

MEDIA DESCRIPTION

*Motor assemblies include

motor, capacitor and

connector.

DISKETTE

PART

MODEL

NUMBER

DESCRIPTION

SA1 00

50417

IBM 3740 Compatible,

DECORATIVE FACEPLATES
Single Density
Size

SA101

50418

SA1 03

50646
50708

Double Denisty

M 2 FM

32 Sector, Double Density

Tan
White

4-5/8x10-1/2
4-5/8x10-1/2

sity

SA1 02

Color Part

Numbers

32 Sector, Single Den-

5-1/4x10
5-1/4x10
5-1/4x11
5-1/4x11

Rack

Mount

Tan

50261

White

50260
50258
50257
50675

Tan
White

4-5/8x8-11/16

50264
50263

Tan

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