Wolf_Research_Whirlwind_I_Checkout_Progress_Report_Jul63 Wolf Research Whirlwind I Checkout Progress Report Jul63
Wolf_Research_Whirlwind_I_Checkout_Progress_Report_Jul63 Wolf_Research_Whirlwind_I_Checkout_Progress_Report_Jul63
Wolf_Research_Whirlwind_I_Checkout_Progress_Report_Jul63 Wolf_Research_Whirlwind_I_Checkout_Progress_Report_Jul63
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WHIRLWIND
I
MOVING,
REASSEMBLY
ANI;?
CHECKOUT
PROGRESS
REPORT
JULY
1963
by
Albert
V.
Shortell,
Jr.
WOLF
RESEARCH
AND
DEVELOPMENT
CORPORATIO\N,
Baker
Avenue
and
Route
2
West
Concord,
Massachusetts
'w
0,1'
Research
and
Development
Corporation
P.O.
Box
136;
Baker
Avenue,
West
Concord,
Massachusetts
EMerson
9-211
1
Mr.
Alfred
J.
Wis
e
Special
Representative
Office
of
Naval
Research
Massachusetts
Institute
of
Technology
Cambridge
39,
Mass
achusetts
Dear
Mr.
Wi~e:
August
16,
1963
We
are
enclosing
a
report
on
the
current
st~tus'
of
the
moving,
reassembly
and
check-out
of
the
Whirlwind
I
Computer.
This
report
summarizes
the
activities
and
events
compris'ing
·the
moving
and
1"e-
assemb,ly
phase
and
the
check-out
phase.
The
activities
and
events
of
these
two
phases
are
also
portrayed
by
means
of
two
PERT
networks.
The
PER
T
network
descr-ibing
the
cheek-out
phase
presents'
scheduled
dates
for
completing
the
remaining
events
prerequisite
to
complete
computer
check-out.
While
these
scheduled
dates
are
based
on
our
present
best
estimates,
unforeseen
problems
may
cause
a
further
slip-
page
in
this
s
ched
ule
.
Although
this
report
provides
considerable
detail
as
to
the
pre-
sent
status
of
computer
checkout,
a
visual
demonstration
of
actual
com-
puter
operation
is
more
impress
ive
particularly
now
that
we
have
a
few,
of
the
Whirlwind
display
demonstration
programs
operating.
We
would
therefore
like
to
extend
an
invitation
to
you,
Mr.
Healy,
Professor
Wilson
and
other
ONR
personnel
to
visit
us
again
soon
for
the
purpose
of
such
a
demonstration.,
' -
AVS/
csn
Enc~osures
Very
truly
yours~
~${.4M.
William
M.
wOlf-'
President
I
II
III
TABLE
OF
CONTENTS
INTRODUCTION.
. . . .
MOVING
AND
REASSEMBLY
..
1
·2
A.
Rigging
and
Moving...
. •
t.
• 2
3
3
4
B.
C.
D.
Air
Conditioning
Installation
Power
Equipment
. . . . . . . . . .
Mechanical
and
Electrical
Reassembly.
COMPUTER
CHECKOUT
. .
13
A.
Equipment
Checked
Out.
.
13
1.
Power
Equipment
a.
b.
c.
Standby
Alternator
and
Filament
Power
Distribution
System
. . . . . . . .
DC
Power
Supplies.
. . . . . .
DC
Power
Distribution
System
Marginal
Checking
System
. . . . .
,
/'
13
13
14
14
16
2.
Cont
ro1
Element.
.
17
18
19
v3.
4.
Arithmetic
Element
Storage
Element.
.
a.
Toggle
Switch
Storage
and
Parity
Register
. . .
..
19
/b.
Flip
Flop
Storage
. . .
..
19
c.
Core
Memory
. . .
5.
Input
-Output
Element.
.
20
21
a.
Control......
b.
Peripheral
Equipment
1)
Flexowriter
Keyboard
Input,
Reader/Printer,
21
21
and
Punch
. . . . . . . . . . .
21
2)
Photoelectric
Tape
Reader
. . .
22
.
3)
Real
Time
Clock.
. . . . .
22
/4)
Test
Control
Display
Scopes
22
5)
Intervention:
and
Activate
Registers
23
B.
Table
of
Contents
(Cont'd)
Equipment
to
be
Checked
Out
1.
Power
Equipment.
. . . .
/ct.
400
Amp
Alternator
and
Filament
Power
Distribution
System
. . . .
..
....
b.
DC
Powe
r
Dist
ribution
System.
.
2.
Input
-Output
Equipment.
.
\/a.
Display
Consoles.
.
b.
Indicator
Light
Registers
tiC.
Light
Guns.
. . . . .
d.
(e.
f.
Magnetic
Tape
Units
IBM
Card
Machines
Anelex
Alphanumeric
Printer
g.
Test
Control
Camera
.
h.
Magnetic
Drums
. . .
i.
Teletype
Input
and
Output
IV·
MAJOR
PROBLEMS
ENCOUNTERED
TO
DATE
V
Wire-
Wound
Resistors
A.
B.
C.
D.
400
Amp
Standby
Alternator
Slip
Rings
.
Air
Conditioning
Equipment
Trouble
Phenolic
Breakdowns
..
. . '
..
E.
Power
Failures
SUMMARY
c >
.
,Page
23
23
23
24
25
25
25
26
26
26
.26
27
27
28
33
33
35
36
38
40
42
Figure
2-1
Figure
3~1
Table
2-1
2-2
2-3
2-4
3
-1
LIST
OF
ILLUSTRATIONS
PERT
Network
WWI
Com.puter
Moving
and
Reassembly
PERT
Network
'?fWI
Com.puter
Checkout.
. . . . . .
LIST
OF
TABLES
Rigging
and
Moving
(RM).
. . . . .
Air
Conditioning
Installation
(AC)
.
Power
Equipment
(PE)"
"0
• " • • •
12
32
7
8
9
Mechanical
and
Electrical
Reassembly
(ME)
. " "
..
" "
lq;i~l
Check
Out
(CO)
. "
.....
,.
. . . . . . . " "
29-31
I
INTRODUCTION
This
memorandum
summarizes
the
present
status
of
Whirlwind
I I
computer
checkout
and
de
sc
ribes
the
wo
rk
ac
complished
to
date
in
moving,
reassembling
and
checking
out
the
Whirlwind
I
computer
in
its
new
locat~on.
In
addition,
items
of
equipm~nt
yet
to
be
checked
out
are
desc
ribed
and
scheduled.
Section
II
describes
the
moving
and
reassembly
phase
which
com-
m.enced
on
Decem.ber
6,
1961,
and
was
com.pleted
on
Decem.ber
13,
1962.
A
PERT
network
showing
the
interrelationships
and
completion
dates
of
the
events
comprising
the
m.oving
and
reas
sem.bly
phase
is
also
presented.
Section
III
describes
the
computer
checkout
phase
which
com.m.enced
on
Dec
em.be
r
19,
1962,
and
is
scheduled
for
com.pletion
on
Novem.b
e r
15,
1963.
This
section
describes
both
work
accomplished
to
date
and
work
to
be
accom.plished
by
the
scheduled
date
of
Novem.ber
15,
1963.
Section
IV
describes
the
major
problems
encountered'to
date
in
checking
out
the
com.puter.
1
II
MOVING
AND
REASSEMBLY
The
moving
and
reassembly
phase
commenced
on
December
6,
1961,
and
was
completed
on
December
13,
1962.
Figure
2
-1
is
a
PERT
network
which
depicts
the
interrelationships
of
events
comprising
this
phase.
Events
are
described
by
the
circular.
disks
and
the
activities
leading
to
these
events
are
described
by
the
printed
paper
tape
whose
length
is
proportional
to
the
time
required
for
the
activity.
Unprinted
tape
represents
activities
which
require
no
time
while
unlabeled
disks
are
merely
connectors
and
do
not
rep-
resent
events.
Tables
2
-1
through
2
-4
inclusive
identify
each
of
the
events
in
this
network.
The
labeling
of
these
events
is
similar
to
that
used
in
our
memorandum
"Schedule
for
Moving
and
Reassembling
the
Whirlwind
I
Computer"
dated
October
6,
1960.
Modification
and
additions
to
the
tasks
listed
therein
have
been
made
where
necessary.
A.
Rigging
and
Moving
The
events
associated
with
rigging
and
moving
are
listed
in
Table
2-1.
Moving
of
the
air
conditioning
cooling
towers
(RMll)
and
ductwork
(RM13)
was
accomplished
on
December
8,
1961,
and
the
air
handling
units
and
associated
controls
(RM12A)
were
moved
on
January
16,
1962.
Due
to
delays
in
building
construction,
the
moving
of
the
main
computer
racks
(RM3,
RM4,
RM5
and
RM7),
which
was
originally
scheduled
for
December,
was
delayed
until
February.
Following
this,
the
end
wall
of
the
computer
section
of
the
building
was
completed.
The
moving
of
rotating
machinery
and
associated
switch
gear
(RM14),
DC
power
supplies
(RM15),
and
air
conditioning
compressors
(RMlO)
had
to
be
delayed
until
the
completion
of
the
mechanical
room
section
of
the
building.
These
latter
units
were
moved
and
set
up
in
place
by
the
latter
part
of
March,
1962.
Due
to
internal
con-
struction
work
such
as
electrical,
plumbing
and
heating,
and
painting,
the
equipment
racks
could
not
be
spread
out
and
positioned
until
early
April.
This
was
done
during
the
period
April
5,
1962
through
April
13,
1962,
inclusive,
and
is
described
by
events
RM6,
RM8
and
RM17.
Other
events
listed
under
rigging
an~
moving
in
Table
2
-1
were
accomplished
at
our
con-
venience
as
the
equipment
was
needed
but
were
scheduled
so
as'
to
vacate
Navy
Building
61
in
South
Boston
before
termination
of
our
lease
extension
on
June
30,
1962.
2
During
the
moving
of
additional
equipment,
it
soon
became
obvious
that
additional
storage
space
more
convenient
to
Concord
was
a
necessity.
Consequently,
8400
square
feet
of
warehouse
space
was
leased
in
Maynard,
Massachusetts.
While
not
shown
explicitly
on
the
PERT
network,
the
space
at
Building
61
in
South
Boston
was
vacated
on
or
about
May
29
J
1962.
Events
RMl
and
RM16
represent,
respectively,
the
moving
from
Maynard
to
Concord
of
panels
removed
from
the
computer
and
the
completion
of
the
moving
of
additional
equipment
stored
in
our
Boston
office
and
in
quarters
adjac
ent
to
our
new
building
in
Conc
0
rd.
B.
Air
Conditioning
Installation
Table
2-2
describes
the
events
associated
with
air
conditioning
equipment
installation.
The
installation
of
the
air
conditioning
equipment
com-
menced
on
May
23,
1962,
with
the
installation
of
ductwork
(AC3A)
and
elec-
trical
switchgear
and
control
wiring
(AC4A).
Installation
of
refrigerant
piping
(ACl)
was
started
early
in
June
and
was
completed
on
July
31.
Cornpletion
of
the
rnajority
of
the
ductwork
(AC3C)
and
electrical
wiring
(AC4B)
as
well
as
pneumatic
control
installation
(AC2B)
was
accomplished
by
August
2.
Charging
of
the
system
with
Freon
and
check
out
of
the
basic
system
(AC5B)
was
accomplished
on
August
4,
1962.
Completion
of
remaining
air
conditioning
work
had
to
be
delayed
until
receipt
of
a
n~w
cooling
coil
for
the
air
handler
which
provides
room
air
cooling.
This
coil
was
received
during
the
latter
part
of
September
and
completion
of
all
air
conditioning
work
(AC2C,
AC3D,
AC4C,
AC4D,
and
AC5C)
was
accomplished
on
October
18,
1962.
C.
Power
Equipment
The
tasks
involved
in
installation
of
power
equipment
are
listed
in
Table
2
-3.
Two
of
the
twelve
events
listed
in
this
table
were
purpos
ely
ornitted
from
the
reassembly
phase
of
the
project
in
order
to
perrnit
an
earlier
start
of
the
computer
checkout
phase.
These
two
events,
namely
..
the
wiring
and
checkout
of
the
400
amp
alternator
(PEl
and
PE5B)
affect
only
the
special
input-output
equipment,
particularly
the
magnetic
drums
and
thus
were
not
essential
to
the
checkout
of
the
main
computer.
These
events
are
yet
to
be
accomplished
but
are
scheduled
on
the
PERT
network
presented
in
3
Section
III.
A
third
event
listed
in
Table
2
-3
(PEB)
has
been
completed
but
is
shown
on
the
PERT
network
of
Section
III
since
it
is
more
properly
con-
sidered
as
a
checkout
event
rather
than
a
reassembly
event.
The
remaining
events
listed
in
Table
2
-3
are
portrayed
in
the
PERT
network
of
Figure
2-1.,
These
commenced
during
the
latter
part
of
March,
1962
and
were
completed
on
December
13,
1962.
These
tasks
in-
volved
the
setup
and
wiring
of
the
400
amp
standby
alternator,
associated
power
control
racks
and
contactors
(PE2,
PE3A,
PE3B,
PE4,
and
PE5A),
installation
and
wiring
of
computer
DC
power
supplies
(PE6A,
PE6B,
PE7,
and
PE9)
and
wiring,
checkout,
and-
distribution
of
laboratory
DC
power
(PEIO
and
PE
11).
D.
Mechanical
and
Electrical
Reassembly
The
events
associated
with
mechanical
and
electrical
reassembly
of
the
computer
are
listed
in
Table
2
-4.
All
but
the
last
four
events
in
this
table
were
completed
during
the
moving
and
reassembly
phase
and
are
por-
trayed
in
the
PERT
network
of
Figure
2-1.
The
last
four
events
are
scheduled
on
the
PERT
network
of
Figure
3
-1.
One
of
these
events
(ME23)
has
been
completed
and
the
remaining
three
(ME24,
ME25
and
ME26)
are
scheduled
for
completion
within
the
next
ten
days.
These
four
events
were
purposely
eliminated-from
the
moving
and
reassembly
phase
since
they
could
be
con~
veniently
postponed
without
delaying
the
start
of
the
checkout
phase
of
the,
project.
The
remaining
events
associated
with
mechanical
and
electrical
reassembly
were
started
early
in
April,
1962
and
were
completed
on
-
November
15,
1962.
It
should
be
pointed
out
that
one
of
these
events
(ME14)
was
intentionally
deleted
from
the
PERT
chart,
since
after
a
few
weeks
of
checking
it
was
concluded
that
the
error
rate
of
Northeastern
students
in
reconnecting
cables
was
sufficiently
low
to
make
exhaustive
checking
of
cables
unnecessary.
It
was
decided
that
if
power
connections
were
checked
out
in
a
fail-safe
manner
that
signal
cabling
errors
could
be
tolerated
without
damage
to
the
computer.
This
decision
to
bypass
checking
of
wire
and
cable
reconnections
in
great
detail
saved
considerable
time
and
has
been
proven
to
be
a
correct
decision
4
during
the
checkout
phase
which
is
described
in
Section
III.
While
exact
figures
on
the
error
rate
in
reconnecting
cables
have
not
been
kept,
our
best
estimate
is
that
this
error
rate
was
not
more
than
50/0
and
was
probably_
as
low
as
2
to
30/0.
Considering
the
semi-skilled
personnel
perform.ing'
this
task,
the
fact
that
two
different
groups
disconnected
and
reconnected
the
cables,
and
inevitable
human
error
in
recording
and
interpreting
cable
termination
data,
we
feel
that
this
record
is
extremely
good.
While
the
mechanical
and
electrical
reassembly
phase
consisted
of
about
25
different
tasks,
the
major
portion
of
the
job
involved
re-
connection
of
wires
and
cables
(ME13).
This
task,
which
was
started
on
April
30,
was
cOlTIpleted
on
October
29.
It
shoul?
be
pointed
out
here,
that
thfs
reconnection
included
all
the
ca_ble s
which
were
disconnected
at
Cambridge,
not
only
in
the
main
computer
but
in
the
input-output
equipment
area
associated
with
drums,
radar
and
teletype
inputs,
and
digital
outputs.
Thus,
this"task
involved
about
twice
as
much
work
as
that
defined
as
MEl3
in
our
memorandum
nSchedule
for
Moving
and
Reassembling
the
Whirlwind
I
Computer"
dated
October
6,
1960,
wherein
we
had
planned
to
reconnect
only
those
cables
associated
with
the
central
computer.
Other
factors
tending
to
lengthen
this
task
included
the
fabrication
of
new
cables
to
replace
ones
which
were
badly
frayed
and
tangled
at
Cambridge,
extending
or
replacing
cables
which
proved,
in
a
few
cases,
to
be
too
short
due
to
our
relocation
of
test
control
relative
to
the
main
computer,
and
time
spent
in
pulse
checking
each
video
cable
prior
to
reconnection.
Pulse
checking
of
video
cables
has
proven
valuable
during
the
checkout
phase
since
the
only
video
cable
failures
found
to
date
during
checkout
have
been
in
cables
which
were
disconnected
only
at
one
end
and
which
could
not
be
pulse
checked
since
their
destinations
were
not
known
without
considerable
checking
of
MIT
records.
All
other
events
associated
with
mechanical
and
electrical
reassembly
required
relatively
short
times
for
their
completion.
For
example,
events
MEl
through
ME7
inclusive
were
completed
during
the
month
of
April,
1962.
Other
events
which
appear
later
during
the
schedule
shown
in
the
PERT
network
of
Figure
2
-1
involved
effort
of
a
few
days
to
two
weeks
and
were
accomplished
as
required
and
as
time
permitted.
The
activity
paths,to
most
of
these
events
represent
time
delays
primarily.
For
example,
5
about
22
weeks
elapsed
between
the
installation
of
computer
wireways
and
ground
busses
(ME5)
and
the
completion
of
reconnecting
computer
wires
which
we
had
cut
in
Cambridge
(ME
11).
This
latte
r
event
(ME
11)
required
about
a
week
of
effort
for
its
accomplishment.
but
due
to
manpower
limita-
tions
was
not
started
until
the
,middle
of
September,
,1962.
This
manpower
limitation
was
dictated
primarily
by
efficiency
considerations,
since
the
size
of
the
work~ng
crew
was
about
optimum,
an
increase
in
its
size
..
would
have
resulted
in
decreased
effectiveness
of
the
group.
6
7
TABLE
2-1
Rigging
and
Moving
(RM)
Date
Completed
Event
No.
Desc
ription
or
Scheduled
RM1
Removed
Panels
Moved
July
21,
1962
RM2
Transformer
Panels
Moved
April
15,
1962
RM3
Test
Control,
Core
Banks
and
February
13,
1962
Drums
Moved
RM4
Computer
Racks
0-7
Moved
February
9,
1962
RM5
Computer
Racks
8-15
Moved
February
9,
1962
RM6
Computer
Racks
Positioned
April
10,
1962
RM7
I/O
'Racks
Moved
February
9,
1962
RM8
I/O
Racks
Positioned
April
13,
1962
RM9
Wire
Boxes
Moved
April
15,
1962
RMIO
Compressors
Moved
and
Set
Up
March
26,
1962
RMll
Evaporators
Moved
and
Set
:UP
December
8,1961
RM12A
Air
Handling
Units
and
Control
January
16,
1962
Boards
Moved
RM12B
Air
Handling
Units
Set
Up
February
7,
1962
RM13
Ductwork
Moved
December
8,
1961
RM14
Rotating
Mac;:hinery
and
Switch-
March
26,
1962
gear
Moved
and
Set
Up
RM15
DC
Supplies
Moved
March
2'3,
1962
RM16
Remaining
Equipment
Moved
June
12,
1962
RM17
TC
Rack$
Positioned
April
5,
1962
Event
No.
ACI/
AC2A
~/
AC2B
AC2C
AC3A//,
AC3B
J
AC3C
AC3D
/'
AC4A
,ft_/'
AC4B
AC4C
AC4D
.AC5A
1/'-
AC5B
1-
AC5C
TABLE
2-2
Air
Conditioning
Installation
(AC)
Description
Refrigerant
Piping
Com.pleted
Sta
rtConnecting
Pneum.atic
Controls
Com.plete
all
Pneumatic
Controls
Except
Room
and
Mechanical
Room.
Complete
all
Pneumatic
Controls
Start
Ductwork
Installation
Complete
Fresh
Air
And
First
Section
Supply
Ducts
Complete
all
Ductwork
Except
Room
and
Mechanical
Room
Complete
all
Ductwork
Start
Electric
Switchgear
and
Control
Wiring
Complete
all
Wiring
Except
Room
and
Mechanical
Room
Controls
Start
Remaining
Wiring
Complete
all
Wiring
Start
System
Checkout
Complete
Basic
System.
Checkout
Complete
System
Checkout
Date
Completed
or
Scheduled
July
31,
1962
August
1,
1962
~\
August
2,
1962
September
27,
1962
May_
28,
1962
JUly
6,
1962
August
2,
1962
September
27,
1962
May
28,
1962
July
29,
1962
October
12,
1962
October
15,
1962
August
3,'
1962
August
4,
1962
October
18,
1962
8
9
TABLE
2-3
Power
Equipment
(PE)
Date
Completed
Event
No.
Desc
ription
or
Scheduled
*
PEll
400A
Alternator
Wired
August
14,
1963
PE2
~
400A
Standby
Alternator
Wired
June
22,
1962
PE3A
I-
Power
Control
Racks
Set
Up
April
6,
1962
;PE3B
c/
Power
Control
Racks
Wired
October
15,
1962
PE4
Filament
Contacto
r s
Wired
to
October
26,
1962
Busses
PE5A
1"/
Standby
Alternator
Checked
Out
December
13,
1962
*
PE5B
400A
Alternator
Checked
Out
August
20,
1963
PE6A
j--'
DC
Supplies
Installed
in Racks
June
9,
1962
PE6B
/'
DC
Supplies
Wired
October
12,
1962
PE7
//'
AC
Inputs
to
DC
Supplies
Wired
October
12,
1962
**
PEB
DC
Supplies
Checked
Out
January
17,
1963
PE9
y"
DC
Supplies
Wired
to
Busses
August
17,
1962
PEI0
v'
Lab.
DC
Supplies
Wired
and
June
29,
1962
Checked
Out
PE11
Lab.
DC
Distribution
Completed
October
16,
1962
*
Incomplete
as
of
July
31,
1963.
Desc
ribed
and
scheduled
in
Section
III.
**
Des(f:ribed
and
scheduled
in
Section
III.
Event
No.
MEl
MEl
ME3
ME4
ME5
ME6A
ME6B
ME7
v
r
)//
r
j/'
ME8
' .
ME9A
,!,.,.,.".
ME9B
l:r
ME9C':,- v
MElO
","'"
MEll
V
MEl2
MEl3A
t
MEl3B
~.
ME14
. f-.-/
ME15
TABLE
2-4
Mechanical
and
Electrical
Reas
sembly
(ME)
Dese
ription
Floor
Marked
for
Computer
Racks
Floor
Marked
for
TC
Racks
Floor
Marked
for
I/O
Racks
Junction
Box
Mount
Completed
Computer
Wireway
and
Ground
Bus
Installed
Start
'Test
Control
Wireways
Test
Control
Wireways
Installed
I/O
Wireways
and
Ground
Bus
Installed
Removed
Panels
Replaced
Transformer
Panels
Replaced
Transformer
Panels
Rewired
Filter
Panels
Replaced
Bus
Ba
r s
Installed
Computer
Cut
Wires
Reconnected
I/O
Cut
Wires
Reconnected
Start
Reconnection
of
Wires
and
Cables
Reconnection
of
Cables
Completed
Reconnectionof
Cables
Checked
Out
Interco;rn
Reconnected
and
Checked
Out
Date
Completed
or
Scheduled
April
6,
1962
April
2,
1962
April
10,
1962
April
18,
1962
April
26,
1962
April
16,
1962
April
27,
1962
April
27,
1962
JUly
26,
1962
April
20,
1962
August
10,
1962
November
15,
1962
July
18,
1962
September
26,
1962
September
27,
1962
April
30,
1962
October
29,
1962
Deleted
September
14,
1962
10
11
TABLE
2-4
Mechanical
and
Electrical
Reassembly
(ME)
(Cont'd)
Date
Completed
Event
No.
Description
or
Scheduled
ME16
j,-/
Transformers
in
Banks
A
and
B
October
25,
1962
Replaced
ME17
p/
Core
Stacks
A,
Band
C
Installed
October
29,
1962
ME18
j/
Drum
Bearings
Checked
and
September
24,
1962
Replaced
if
Required
ME19
["./
Drums
Installed
September
28,
1962
ME20
AC
and
DC
Power
for
TC
October
3,
1962
Installed
ME2l
v J
unction
Boxed
Repo
s
itioned
October
5,
1962
ME22
Test
Bench
for
Drum
Chassis
September
24,
1962
Installed
I I
**
1963
ME23
1-/
Construct
Anelex
Transition
Panel
April
11,
*
ME24
y/
Install
Anelex
Cabling
"
August
9,
1963
I.,
*
ME25
y
Repair
Brush
Box,es
on
400A
August
9,
1963
Alternator
*
/'
Recable
3
Display
Consoles
ME26
August
2,
1963
* ;
Incomplete
as
of
July
31,
1963.
De,scribed
and
scheduled
in
Section
III.
>:C*Described
and
scheduled'in
Section
III.,
III
COMPUTER
CHECKOUT
The
checkout
phase
commenced
on
December
19,
1962
with
the
completion
of
checking
the
standby
alternator
cycling
system
from
the
alternator
output
to
the
computer
busses
and
thence
to
the
computer
racks.
That
is,
filament
power
was
applied
to
all
of
the
main
computer
racks.
Checkout
,is
scheduled
to
be
completed
on
Novembe
r
15,
1963
with
the
com
-:.
'.
pletion
of
checkout
of
the
teletype
input
subsystem.
Presented
in
Figure
3-i
is
a
PERT
network
which
describes
the
activities
and
events
comprising
this
phase
of
the
project.
All
but
seven
of
the
events
in
this
network
are
listed
in
Table
3
-1.
As
mentioned
in
Section
II,
the
remaining
seven
event's,
(PEl,
PE5B,
PEB,
ME23, ME24,
ME25,
and
ME26)
have
been
carried
over
from
the
moving
and
reassembly
phase
as
their
accomplishment
was
not
essential
to
the
start
of
the
checkout
phase
and
it
was
more
convenient
to
defer
action
on
these
tasks.
These
tasks
are
described
in
Tables
2-3
and
2
-4
of
Section
II.
Two
of
these
seven
events
(PEB
and
ME23)
have
already
been
accomplished;
the
remaining
five
are
scheduled
to
be
completed
within
the
next
three
weeks.
It
should
be
noted
that
our
October,
~960
moving
schedule
memorandum
has
no
counterpart
of
Table
3
-1,
since
the
1960
! I
memorandum
scheduled
only
the
moving
and
reas~embly
but
not
the
checkout
of
the
computer.
Section
A
below
describes
equipment
already
checked
out
during
the
checkout
phase,
while
Section
B
describes
tasks
involving
equipment
yet
to
be
checked'
out.
A.
Equipment
Checked
Out
1.
Power
Equipment
13
a.
Standby
Alternator
and
Filament
Power
Distribution
System)
As
mentioned
above,
the
checkout
phase
began
on
December
19,
1962
with
the
success~ul
completion
of
checking
of
cycling
of
the
standby
alternator
to
the
computer
busses
(COl)
and
thence
to
the
computer
racks
(C02).
These
two
events
were
completed
with
very
little
difficulty.
Power
was
cycled
on
to
groups
of
eight
racks
at
a
time
with
several
personnel
st~nding
by
to
warn
of
trouble
so
that
power
could
be
reITloved
immediately,
thereby
minimizing
damage
to
the
computer
panels.
As
power
was
applied
succes
sfully
to
each
group
of
eight
racks,
the
filament
voltage
was
then
cycled
down,
eight
more
racks
were
turned
on
and
observed
for
signs
of
trouble
as
the
filaments
were
cycled
back
on.
This
procedure
of
adding
modules
of
eight
racks
to
previously
checked
racks
with
alternate
cycling
on
and
off
of
the
filament
power
was
repeated
until
filament
power
was
success-
fully
applied
to
all
the
racks
in
the
main
computer
including
the
core
memories.
The
success
of
this
operation
is
indicated
by
the
fact
that
the
entire
process
was
completed
in
a
period
of
about
four
hours.
Other
than
a
difficulty
due
to
voltage
breakdown
in
the
standby
alternator
slip
rings,
which
occurred
on
April
12
a.nd
which
is
described
in
Section
IV
-B,
<l.nd
q,
few blown filament
fuses
due to loose connections,
the
filament
alternator
cycling
and
power
dis-
tribution
system
has
worked
exceedingly
well
to
date.
b.
DC
Power
Supplies
Checkout
of
the
computer
DC
power
supplies
with
dummy
loads
(PEB)
was
accomplished
on
January
17,
1963.
While
this
task
was
rather
time
consuming,
it
was
accomplished
with
very
little
difficulty.
Of
the
twelve
supplies
involved,
trouble
was
encountered
with
only
about
three
of
them
and
these
were
cured
by
replacing
tubes
and/
or
wire
-wound
resistors.
The
proble:m
of
open
wire
-wound
resistors
in
the
power
supplies
is
similar
to
that
encountered
elsewhere
in
the
computer
and
this
problem
is
described
more
fully
in
Section
IV
-A
•.
With
the
exception
of
the
-48
volt
supply
which
has
a
war:m-up
problem
which
existed
at
MIT
and
the
occas
sional
tripping
of
the
main
circuit
breaker
on
the
+150
volt
supply
due
to
a
weak
breaker,
these
equipments
have
worked
extremely
well
ever
since
they
were
first
checked
out.
The
-48
volt
supply
problem
is
due
to
a
thermistor
in
the
regulator
·circuit
which
must
be
preheated
by
a
light
bulb
before
it
will
regulate
properly.
These
two
problems
can
probably
be
cured
by
replacing
the
thermistor
and
the
circuit
breaker,
but
their
replacement
is
of
fairly
low
priority
at
present,
since
they
cause
very
slight
inconvenience
when
first
turning
on
the
computer.
c.
DC
Powe
r
Distribution
System
.After
checking
out
the
DC
power
supplies
with~
dummy
loads,
the
next
step
was
tp
check
the
connections
of
these
supplies
to
the
14
computer
busses
and
thence
through
the
power
distribution
circuits
to
the
individual
computer
racks.
These
tasks
(C03
and
C04)
were
accomplished
during
the
period
from
January
17
to
February
28,
1963.
Checking
the
connections
of
the
supplies
to
the
computer
busses
involved
checking
the
proper
sequencing
of
the
power
supply
timers
to
ensure
that
the
voltages
were
applied
to
the
busses
in
their
proper
sequence.
This
task
(C03)
required
but
four
days.
The
task
of
checking
the
distribution
of
DC
voltages
from
the
busses
through
the
power
distribution
system
to
the
individual
racks
was
considerably
more
complicated.
Several
precautions
had
to
be
taken
to
prevent
damage
to
the
computer
panels
due
to
incorrect
voltages
being
applied
as
a
result
of
wiring
errors
in
reconnecting
the
cables.
As
mentioned
in
Section
II-D,
extensive
checking
of
power
cabling
reconnections
was
bypassed
after
determining
that
the
error
rate
was
extremely
small.
However,
errors
were
known
to
exist
and
in
checking
the
DC
distribution
to
the
individual
racks
not
a
single
error
could
be
tolerated.
Since
most
of
the
panels
had
never
been
disconnected
from
their
respective
rack
terminal
strips,
the
connections
from
these
terminal
strips
to
the
individual
panels
were
known
to
be
correct.
However,
the
connections
from
the
power
distribution
circuits
to
the
rack
terminal
strips
had
been
disconnected
and
required
thorough
checking.
A
simple
means
for
making
this
check
was
devised
which
enabled
us
to
apply
power
to
the
rack
terminal
strips
without
simultaneously
applying
power
to
the
individual
panels.
This
procedure
was
to
open
up
the
fuse
links
in
the
rack
terminal
strips
by
placing
wooden
coffee
stirrers
between
the
line
side
of
the
fuse
and
the
terminal
to
which
it
is
normally
connected.
This
disabled
the
power
connections
to
the
panels
without
removing
the
fuses
and
the
voltage
at
each
terminal
of
each
rack
was
checked
with
a
voltmeter
and
verified
with
the
MIT
rack
wiring
schedules
to
ensure
that
all
the
voltages
we~e
applied
at
the
proper
points.
Fewer
than
twenty
wires
were
found
to
be
in
error
out
of
a
total
of
7000
to
10,000
terminals
which
had
to
be
checked.
A
few
racks
were
found
to
have
no
voltage
and
these
troubles
were
usually
traced
to
wiring
errors
in
the
power
distribution
system.
The
operation
of
the
power
dis-
tribution
system
which
contains
somewhere
in
the
order
of
2000
relays
has
15
been
extremely
good.
Not
a
single
relay
had
to
be
replaced
due
to
faulty
operation
during
checkout
and
none
have
had
to
be
replaced
since.
d.
Marginal
Checking
System
Checkout
of
the
margina"i
checking
syst~m
was
not
essen-
tial
to
initial
checking
of
the
com.puter
circuits
and
was
therefore
postponed
until
April
1.
Another
reason
for
delaying
the
checkout
of
this
equipment
is
that
the
motor
which
drives
the
amplidyne
generator
was
wound
for
115
volt,
three
phase
operation.
In
Cambridge
this
motor
was
fed
from
a
230
volt,
three
phase
transformer
bank
through
a
small
230/115
vO,lt,
three
phase
transformer
banl<..
As
MIT
retained
the
230
volt
transformer
bank
at
the
Barta
Building,
we
had
no
means
of
feeding
the
230
volt
input
to
the
230/115
volt
transformer
bank
associated
with
the
marginal
checking
equipment.
It\.
was
found
to
be
more
desirable
and
less
expensive
to
have
the
motor
of
the
amplidyne
generator
rewound
for
120/208
volt,
three
phase
operation
and
the
spare
amplidyne
unit
was
sent
to
General
Electric
to
be
rewound
in
this
fashion.
Having
received
the
rewound
amplidyne
from.
GE,
and
having
en-
countered
difficulty
with
marginal
flip
flops
in
checking
the
computer
circuits,
it
was
decided
on
April
1
to
concentrate
our
efforts
on
making
the
marginal
checking
system
operational.
The
greatest
difficulty
with
the
marginal
checking
system
was
encountered
with
the
regulator
which
controls
the
output
of
the
amplidyne.
Due
to
interruptions
caused
by
shorting
of
the
slip
rings
on
the
400
amp
standby
alte
rnator
and
the
burning
up
of
a
wire
from
the
filament
bus
se
s
to
the
magnetic
tape
units
as
well
as
concurrent
work
on
checking
of
the
storage
switch,
work
on
the
marginal
checking
regulator
panel
was
not
completed
until
the
latter
part
of
April.
When
a
recheck,
of
the
regulator
panel
was
made
at
.
that
time,
it
was
determined
that
the
trouble
was
a
pa
rasitic
oscillation
whose
cause
was
traced
to
a
wiring
error
we
had
made
earlier
in
replacing
the
open
8
watt
wire-wound
resistors
in
the
panel.
After
correcting
this
trouble,
the
marginal
checking
system
worked
properly
and
its
operation
has
been
very
satisfactory
since
then.
During
the
period
from
about
April
8
to
April
30,
the
marginal
checking
system
was
usable
but
was
failing
to
return
to
zero
from
a
16
positive
margin.
Other
troubles
with
the
marginal
checking
system
corrected
during
the
month
of
April
were
cured
by
replacing
a
broken
wire,
cleaning
some
relay
contacts
in
the
marginal
checking
control
rack,
replacing
a
shorted
electrolytic
capacitor
and
a
faulty
thyratron
and
correcting
two
other
wiring
errors.
2.
Cont
rol
Element
Having
checked
DC
connections
to
the
computer
racks
on
Frbruary
28,
'1963,
the
next
step
was
to
check
the
logical
operation
of
the
computer.
At
this
point,
the
obvious
step
was
to
try
to
operate
the
entire
central
computer
exclusive
of
magnetic
core
storage
and
input-output,
even
though
the
probability
of
success
was
extremely
low.
This
was
t:ried
b-g,t
waf;i
unsuccessful
as
was
expected) and
it
was
then
necessary
to
investigate
the
basic
components
of
the
system
in
more
detail
starting
with
the
Control·.
Element.
The
first
step
was
to
check
the
Pulse
Generator,
Frequency
Divider,
and
Restorer
Pulse
Generator
(C06)
which
are
the
primary
sources
of
all
pulses
used
in
the
machine.
Having
done
some
checking
of
these
units
last
summer
using
laboratory
DC
power
and
unregulated
filament
power,
it
was
not
unexpected
that
these
were
found
to
be
operating
properly.
In
addition,
Clock
Pulse
Control
(CO?),
the
Time
Pulse
Distributor
(COB),
and
the
Test
Control
Synchronizers
(C09)
which
had
also
been
checked
last
summer
were
found
to
be
operating
properly.
The
next
items
to
be
checked
were
the
Control
Switch
(COlI),
the
Operation
Matrix
(COI2),
and
the
Control
Pulse
Output
Units
(COI3).
These
units,
which
decode
the
five-bit
operation
code
portion
of
the
Whirlwind
instruction
word
and
transmit
pulses
to
approprop.riate
sections
of
the
computer
on
the
various
time
pulses
of
the
selected
instruction,
were
checked
out
by
March
15,
1963
with
only
slight
difficulties
which
included
replacing
17
a
shorted
tube,
a
shorted
diode
in
the
matrix)
and
a
loose
video
cable
connector.
Very
little
difficulty
has
been
encountered
with
these
units
since
that
time.
The
next
major
unit
within_
the
Control
Element
to
be
checked
was
the
Program
Counter.
It
was
at
this
point
that
we
encountered
our
first
major
obstable
·to
checking
out
the
computer.
The
Program
Counter,
which
determines
the
location
in
storage
from
which
the
next
instruction
is
to
be
taken)
was
found
to
have
trouble
with
certain'
of
its
flip-flops)
which
developed
a
parasitic
oscillation,
when
pulsed
at
certain
frequencies)
typical
of
those
to
be
encountered
in
computer
operation.
This
difficulty
was
found
to
be
caused
by
the
2000
ohm
ten
watt
resistors
which
had
been
used
to
replace
the
open
2000
ohm
eight
watt
resistors
in
all
the
computer
flip-flop
circuits.
This
difficulty
is
described
in
more
detail
in
Section
IV
-A.
After
replacing
all
of
the
2000
ohm
ten
watt
resistors
with
2000
ohm.
twelve
watt
resistors
and
replacing
several
pairs
of
flip-flop
tubes,
the
Program
Counter
was
made
operational
on
April
23)
1963.
The
remaining
units
of
the
Control
Element)
namely
the
Check
Register
(C020)
and
the
Alarm
System
(COlO)
were
checked
out
a
couple
of
weeks
later
in
connection
with
checking
of
the
Arithmetic
Element
and
the
Storage
Element.·
This
was
necessitated
by
the
fact
that
the
Check
Regist,er
is
used
to
check
transfers
of
data
between
the
Arithmetic,
Control
and
Storage
elements
of
the
computer.
Thus,
we
had
to
be
able
to
transfer
information
between
these
elements
before
determining
the
proper
operation
of
the
Che\ck.",
Register.
In
order
to
obtain
proper
operation
of
the
flip-flops
in
the
Check
Register
panels
it
was
also
found
necessary
to
replace
the
2000
ohm
ten
watt
resistors
with
2000
ohm
twelve
watt
resistors)
and
in
addition,
several
pairs
of
flip-flop
tubes
and
a
few
gate
tubes
had
to
be
replaced.
Checkout
of
the
Alarm
System
was
accomplished
by
correcting
a
few
wiring
errors.
3.
Arithmetic
Element
Initial
checking
of
the
Arithmetic
Element
was
started
around
the
middle
of
April
and
was
completed
on
May
i6,
1963.
This
initial
check
was
concentrated
on
operation
of
the
addition
and
subtraction
instructions.
proper
transfer
of
information
into
and
out
of
the
Arithmetic
Element,
and
improvement
of
the
stability
and
operating
margins
of
the
flip-
flops
within
the
Arithmetic
Element.
Minor
attention
was
given
to
the
multiply,
divide
and
shifting
operations
and
further
work
on
the
'Arithmetic
Element
was
suspended
until
mid-July
in
order
to
proceed
with
the
checkout
of
the
core
memory,
the
input-output,
and
a
few
"F>asic
input-output
devices.
More
detailed
checking
of
the
multiply,
divide
and
shift
operations
was
again
under-
taken
on
July
15
and
was
completed
on
July
30,
1963.
D':lring
the
initial
check
18
of
Arith:metic
Element
operation
(CO
17
A)
most
of
the
troubles
were
corrected
.by
replacing
all
the
2000
ohm
ten
watt
wire
-wound
resistors
with
2000
ohm
twelve
watt
wire-woundresistors
and
replacing
several
of
the
matched
pairs
of
flip-flop
tubes.
The
few
remaining
troubl~s
were
corrected
by
replacing
a
small
quantity
of
gate
tubes
and
rectifying
a
few
video
cabling
errors.
During
the
recent
final
check
of
the
Arithmetic
Element
(C017B)
troubles
with
the
multiply,
divide,
and
shift
instructions
were
found
to
be
caused
by
pulse
repetition
frequency
sensitivity
when
shifting
alternate
l's
and
a's
through
the
flip-flops
of
the
B-Register
and
Accumulator.
Further
investigation
revealed
that
this
sensitivity
could
be
eliminated
by
replacing
the
1600
ohl;'n I
ten
watt
resistors
in
the
flip-flop
circuits
with
1600
ohm
twelve
watt
resistors.
Since
multiplication
is
basically
an
add
and
shift
operation,
and
since
divid,e
is
basically
a
subtract
and
shift
ope
ration,
elimination
of
the
shifting
probl'erns.
also
cured
the
multiply
and
divide
problems.
4.
Storage
Element
a.
Toggle
Switch
Storage
and
Parity
Register
Checkout
of
Toggle
Switch
Storage
and
the
Parity
Register
(GalS)
as
well
as
the
Storage
Switch
was
performed
concurrently
with
the
initial
check
of
the
Arithmetic
Element
and
the
checkout
of
Flip-
Flop
Storage.
This
event
was
accomplished
on
April
22,
1963.
Troubles
with
the
Toggle
Switch
Storage
Registers
and
the
Storage
Switch
were
cor-
rected
by
replacing
ten
watt
resistors
with
twelve
watt
resistors,
replacing
several
defective
6Y6
tubes,
and
by
replacing
several
wires
which
had
been
cut
when
the
computer
was
moved
and
which
had
been
poorly
butt
connected.
Troubles
with
the
Parity
Register
were
cleared
up
mainly
by
replacing
flip-
flop
tubes
and/or
flip-flop
plug-in
units.,
b.
Flip-Flop
Storage
Checkout
of
Flip-Flop
Storage
(CO
16)
also
proceeded
concurrently
with
the
initial
check
of
the
Arithmetic
·Element.
As
with
the
Arithmetic
Element,
most
of
the
troubles
with
Flip-Flop
Storage
were
cor-
rected
by
replacing
2000
ohm
ten
watt
resistors
with
twelve
watt
resistors
and
replacing
several
matched
pairs
of
6145
flip-flop
tubes.
A
few
other
troubles
were
corrected
by
replacing
defective
crystal
diodes
and
correcting
two
wiring
errors
in
the
Flip-Flop
Storage
reset
switches.
19
20
c.
Core
Memory
AC
and
DC
power
were
initially
applied
to
core
memory
Banks
A
and
B
on
May
15
and
to
core
memory
Bank
C
two
days
later.
After
correcting
two
video
cabling
errors
and
replacing
a
defective
video
cable,
proper
operation
of
the
Memory
Address
R~gisters
was
accomplished.
At
this
point
it
was
then
possible
to
attempt
writing
into
and
reading
from
registers
in
each
core
bank.
Parity
errors
were
encountered
in
Banks
A
and
B
but
a
check
of
a
few
registers
in
each
of
the
four
core
fields
in
Bank
C
seemed
to
indicate
that
this
bank
was
working
perfectly.
The
initial
success
of
operation
of
Bank
C
and
initial
failure
of
Banks
A
and
B
was
due,
in
pa
rt,
to
adjustment
of
read
and
write
currents.
Read
and
write
current
controls
in
Banks
A
and
B
had
been
misadjusted
during
the
move)
whereas
the
controls
in
Bank
Care
locked
and
had
not
been
disturbed
by
the
moving
process.
The
current
controls
in
Banks
A
and
B
had
been
roughly
reset
in
accordance
with
some
photographs
we
had
taken
in
Cambridge
prior
to
computer
disassembly.
More
precise
adjustment
of
the
read
and
write
current
controls
in
Banks
A
and
B
with
an
oscilloscope
made
some
improvement
in
operation
of
these
cores
but
did
not
entirely
correct
the
problems.
It
was
then
discovered
that
most
of
the
remaining
troubles
in
Banks
A
and
B
were
due
to
faulty
operation
of
digit
plane
driver
plug-in
units
which
were
failing
to
provide
proper
inhibit
currents
and
\
were
causing
parity
alarms.
Troubles
with
these
plug
-in
unit
digit
plane
drivers
were
found
to
be
due
to
open
ten
watt
non-inductively
wound
resistors.
Since
we
had
good
operation
from
the
4000
core
registers
in
Bank
C
at
that
point,
it
was
decided
to
reduce
our
efforts
on
checking
core
memory
so
that
checkout
of
the
input-output
system,
the
Flexowriter
and
photoelectric
tape
reader
could
be
expedited.
Further
checking
of
Bank
B
suddenly
revealed
that
the
parity
error
problems
were
not
entirely
due
to
faulty
digit
plane
driver
operation
when
it
was
discovered
that
the
cables
from
the
digit
plane
drivers
to
the
core.
planes
had
been
completely
reversed.
Correcting
this
cabling
error
and
repairing
the
digit
plane
drivers
seemed
to
clear
up
all
core
memory
troubles
for
a
period
of
ahout
two
weeks.
However,
with
the
onset
of
very
hot
weather
toward
the
latter
part
of
June,
troubles
developed
in
all
core
banks
and
we
were
suddenly
forced
to
concentrate
all
our
efforts
on
checking
core
memory
again.
Some
of
the
troubles
were
evidenced
by
blown
fuses,
probably
due
to
overheating,
which
resulted
from
a
lack
of
Freon
in
the
air
conditioning
system.
The
system,
as
described
in
Section
IVe,
had
been
found
to
have
lost
all
Freon
during
the
latter
part
of
May.
Over-
heating
problems
during
the
hot
weather
at
the
end
of
June
subsequently
revealed
that
we
had
underestimated
the
Freon
capacity
of
the
system
and
had
replaced
only
about
half
of
the
required
amount
of
Freon.
During
the
first
week
of
July,
a
more
exhaustive
check
of
all
core
banks
was
made.
Troubles
with
Bank
C
were
cleared
up
by
replacing
two
broken
tubes,
two
blown
fuses,
correcting
an
open
circuit
in
a
common
ground
line
on
a
selection
plane
driver
due
to
a
poor
solder
joint,
and
replacement
of
a
burned
out
5998
tube
in
a
selection
plane
driver
panel.
5.
Input
-Output
EleITlent
a.
Control
21
Checkout
of
the
In
-Out
Element
(CO
19)
was
accomplished
with
very
little
difficulty
by
June
5,
1963.
The
only
difficulty
encountered
with
the
In-Out
Register
was
the
failure
of
one
flip-flop
which
was
corrected
by
replac-
ing
the
flip-flop
tubes
with
a
new
matched
pair
of
6145
IS.
Troubles
with
the
In-Out
Delay
Counter
were
corrected
by
replacing
a
missing
gate
tube
and
two
defective
video
cables
which
were
responsible
for
failure
to
terITlinate
block
transfer.
instructions.
Difficulties
with
the
In-Out
Switch
were
corrected
by
replacing
a
missing
6Y6
tube
which
drives
the
clear
line
to
the
flip-flops
of
the
In-Out
Switch
and
by
replacing
an
open
22,
000
ohm
twelve
watt
wire-
wound
resistor
in
a
cathode
follower.
This
cathode
follower
was
failing
to
shut
off
a
gate
tube
in
the
clear
line
to
the
In-Out
Switch
flip-flops
and
was
thus
permitting
spurious
clear
puls~s
to
interfere
with
proper
operation
of
the
In-Out
Switch.
Operation
of
the
In-Out
Element
to
date
has
been
excellent
and
no
failures
have
been
encountered
since
the
above
troubles
were
corrected.
b.
Peripheral
Equipment
1)
Flexowriter
Keyboard
Input,
Reader/Printer,
and
Punch
Checkout
of
the
Flexowriter
direct
keyboard
input,
direct
printer
and
'punch
output
and
mechanical
paper
tape
reader
input
(C022)
was
accomplished
on
June
5,
1963.
The
only
difficulties
encounteredhere
were
caused
by
two
wires
which
were
incorrectly
connected.
2)
Photoelectric
Tape
Reader
Checkout
of
the
Ferranti
Photoelectric
Tape
Reader
(C023)
was
also
accomplished
with
very
little
difficulty.
Three
troubles
were
encountered
here,
two
due
to
missing
DC
voltages,
the
third
due
to
failure
of
one
of
the
digits
to
read
to
the
In-Out
Register.
One
of
the
missing
voltages
was
due
to
a
wiring
error,
the
other
was
due
to
a
broken
wire.
The
failure
to
read
one
of
the
digits
to
the
In-Out
Register
was
corrected
by
tightening
a
tube
which
was
loose
in
its
socket
in
an
In-Out
Register
Input
Mixer
panel.
3 )
Real
Time
Clock
Checkout
of
the
Real
Time
Clock
(C032)
was
com-
pleted
on
June
13,
1963.
Trouble
with
the
clock
was
corrected
by
rectifying
one
video
cabling
error
and
replacing
an
indicator
light
bracket.
4)
Test
Control
Display
Scopes
Successful
completion
of
event
C027
A
was
accom-
plished
on
June
19,
1963.
This
task
included
checkout
of
all
the
control
elements
o.f
the
display
subsystem
as
well
as
the
two
display
scopes
in
Test
Control.
Troubles
encountered
in
this
area
included
failure
of
the
vertical
deflection
signal
which
was
caused
by
a
bad
5651
voltage
regulator
tube
in
the
Vertical
Decoder,
failure
of
vertical
deflection
on
one
scope
due
to
a
loose
22
wire
on
a
binding
post,
and
a
cabling
error
which
caused
the
horizontal
and
vertical
deflection
signals
on
one
scope
to
be
interchanged.
Troubles
with
the
.individual
scopes
were
encountered
in
the
Dumont
high
voltage
power
supplies
and
in
the
deflection
amplifiers.
Troubles
with
the
Dumont
high
voltage
supplies
were
corrected
by
replacing
a
broken
high
voltage
coil
and
two
open
wire
-wound
potentiometers.
Malfunctions
in
one
of
the
horizontal
deflection
amplifiers
were
corr~cted
by
replacing
defective
tubes.
After
correcting
these
dif-
ficulties,
prope
r
operation
of
point
displays,
characte
r
displays,
and
vector
displays
was
accomplished
by
aligning
the
deflection
decoders,
the
decoder
output
amplifier,
and
the
scope
deflection
amplifiers
in
accordance
with
procedures
established
at
MIT.
5)
Intervention
and
Activate
Registers
The
Intervention
and
Activate
Registers
(C02S)
were
also
checked
out
on
June
19.
The
only
difficulties
encounte'red
with
these
subsystems
were
caused
by
missing
voltages
on
the
switches
in,
Test
Control,
two
video
cabling
errors,
and
a
fuse
blowing
problem
associated
with
the
cathode
followers
which
enable
the
read-out
gates
of
the
individual
Intervention
Registers.
The
fuse
involved
kept
blowing
repeatedly
and
the
trouble
was
finally
cleared
up
by
replacing
it
with
a
larger
size
fuse
after
determining
that
the
fuse
rating
was
too
low
for
the
amount
of
current
being
drawn
by
these
cathode
followers.
B.
Equipment
to
be
Checked
Out
Several
more
units
of
input
-output
equipment
remaiI).
to
be
checked
before
the
computer
can
be
considered
to
be
completely
checked
out.
These
include
principally
the
magnetic
tape
units,
the
IBM
card
machines,
the
'Anelex
printer,
three
additional
display
consoles,
and
the
two
magnetic
drums.
In
addition,
the
400
amp
alternator
which
provides
filament
power
to
the
magnetic
drums
and
associated
input
-output
equipment
requires
some
repair
and
must
be
rewired.
Also,
the
power
distribution
system,
both
AC
and
DC,
for
the
magnetic
drums
and
associated
equipment
must
be
checked
out.
Some
checkout
work
has
been
done
in
each
of
these
areas
with
the
exception
of
,the
drums.
Many
of
these
jobs
are
scheduled
to
be
completed
within
the
next
few
weeks
and
present
indications
are
that
all
work
should
be
completed
on
or
about
November
15,
1963.
1.
Powe'r
Equipment
a.
400
Amp
Alternator
and
Filament
Power
Distribution
System
Work
on
repairing
the
brush
boxes
on
the
400
amp
Alternator
(ME25)
is
scheduled
to
start
the
latter
part
of
this
week.
Prelim-
inary
investigation
into
this
problem
indicates
that
replacing
of
the
slip
ring~
may
be
a
more
desirabl,e
long-term
solution.
We
are
awaiting
information
from
the
manufacturer,
which
will
determine
just
how
much
wear
on
the
sl~p
, \
23
rings
has
occurred.
After
talking
with
the
manufacturer's
local
representativ.~,
there
isa
slight
possibility
that
the
solution
to
the
problem
may
be
merely
the
use
of
a
different
type
of
brush
than
that
used
by
MIT.
Data
from
the
factory
giving
original
dimensions
of
the
slip
rings
will
be
the
deciding
factor
on
whether
or
not
these
will
be
replaced.
If
it
is
necessary
to
replace
the
slip
rings,
there
is
a
good
pos
sibility
that
a
new
pair
may
be
available
from
stock.
If
the
slip
rings
are
not
available
from
stock,
then
a
two
week
delivery
~
period
is
quoted.
In
this
latter
event,
it
would
be
necessary
to
postpone
further
work
on
the
slip
rings
for
two
weeks.
However,
other
tasks
as
sociated
with
the
alternator
could
be
performed
sooner
so
that
the
two
week
delivery
delay
.will
not
impose
any
slippage
on
the
existing
schedule.
Reconnecting
the
cables
from
this
400
amp
alternator
(PE
I)
has
been
planned
and
presently
is
scheduled
to
be
accomplished
after
the
slip
ring
problem
is
corrected..
However,
if
it
is
necessary
to
wait
the
two
weeks
for
slip
ring
delivery,
the
wiring
of
the
alternator
can
be
done
first.
Checkout
of
the
400
amp
alternator
(PE5B)
is
presently
scheduled
to
be
completed
by
August
20.
No
difficulty
is
ant,icipated
in
accomplishing
this
task
as
scheduled,
even
if
it
is
necessary
to
wait
two
weeks
for
delivery
of
slip
rings.
After
checking
out
the
operation
of
the
400
amp
alter-
nator,
the
next
tasks
will
be
to
check
the
400
amp
alternator
cycling
system
and
connections
to
the
in-out
filament
busses
(C034)
and
the
filament
con-
nections
to
the
individual
in-out
equipment
racks
and
to
the
drum
bays
(C035).
With
the
exception
of
the
feeder
cables
from
the
400
amp
alternator,
all
the
necessary
filament
power
cycling
and
distribution
wiring
was
completed
during
the
moving
and
reassembly
phase
last
year.
Thus,
little
difficulty
is
foreseen
in
completing
these
two
tasks
by
the
end
of
August.
b.
DC
Power
Distribution
System
After
checking
filament
power
connections
to
the
in-out
equipment
racks
and
drums,
it
will
be
necessary
to
check
the
DC
connections
to
these
equipments.
Two
tasks
are
involved-the
first,
checking
of
the
DC
supplies
to
the
in-out
equipme~t
busses
(C036)
and
the
second,
checking
the
24
DC
power
distribution
to
the
individual
racks
and
drum
bays
(C037).
The
only
difficulties
anticipated
in
connection
with
these
two
tasks
are
in
checking
DC
power
connections
to
the
drum
bays
and
the
connection
9f
rack
DC
switches
which
control
the
outputs
of
the
power
distribution
panels
to
the
associated
racks
and
drum
bays.
Connection
of
the
outputs
of
the
power
distribution
panels
to
the
individual
racks
should
give
no
trouble,
since
unlike
the
racks
in
the
main
computer,
most
of
this
DC
wiring
did
not
have
tobe
disconnected.
The
scheduled
date
of
September
20
for
completion
of
DC
checking
should
be
accomplished
without
difficulty.
2.
Input
-Output
Equipment
With
the
exception
of
the
Anelex
printer,
magnetic
drums,
teletype
input,
and
teletype
output
on
which
no
checking
has
yet
been
done,
checkout
of
remaining
input-output
units
has
been
done
to
some
degree.
a.
Display
Consoles
Three
display
consoles,
in
addition
to
the
two
in
Test
Control
already
checked
out,
are
planned.
Two
of
these
have
been
recabled
and
checkout
is
nearly
completed.
The
third
display
console
recabling
has
just
been
started.
When
cabling
of
this
scope
is
completed,
event
ME26
will
have
been
accomplished.
Completion
of
this
event
is
scheduled
for
August
2,
but
may
slip
one
or
two
days.
Complete
checkout
of
these
three
display
consoles
will
accomplish
event
C03l
'on
or
about
August
7.
The
only
diffi-
culties
anticipated
in
checking
these
three
displays
are
troubles
with
the
Dumont
high
voltage
power
supplies,
alignment
problems
in
the
deflection
amplifiers,
and
a
few
minor
wiring
errors.
b.
.
Indicator
Light
Registers
Completio~
of
checkout
of
all
Indicator
Light
Registers
required
at
present
(C030)
is
expected
to
occur
concurrently
with
the
com-
pletion
of
the
checkout
of
three
display
consoles
mentioned
in
a.
above.
Most
of
these
registers
have
been
checked
and
it
is
felt
that
remaining
troubles
are
due
to
defective
thyratrons
in
these
registers
or
to
one
or
two·
wiring
errors.
25
c.
Light
Guns
Three
light
guns
are
being
checked
out
for
use
with
the
three
display
consoles
mentioned
in
a.
above.
Two
light
guns
have
been
reconnected
and
one
of
these
has
been
checked
out
completed
while
the
third
is
being
connected
with
the
third
display
console.
Completion
of
light
gun
checkout
(C029)
is
also
scheduled
to
coincide
with
the
completion
of
checkout
of
the
three
display
consoles.
No
difficulties
other
than
tube
failure
and
minor
wiring
errors
are
anticipated.
d.
Magnetic
Tape
Units
Checkout
of
the
znagnetic
tape
units
(C026)
is
scheduled
to
be
completed
on
August
12.
Mechanically
these
units
are
operational
as
are
all
the
manual
controls.
Thus,
all
the
remaining
troubles
with
these
units
are
electronic
and
it
is
not
anticipated
that
any
serious
difficulties
will
be
encountered
here.
e.
IBM
Card
Machines
All
the
wiring
for
the
IBM
card
machines
was
checked
very
thoroughly
during
the
moving
and
reassembly
phase
last
fall.
The
IBM
523
gang
summary
punches
used
with
this
system
are
in
good
mechanical
shape.
These
two
machines,
which
were
specially
modified
by
MIT
for
use
26
with
Whirlwind,
were
being
leased
from
IBM
by
MIT.
The
Wolf
Research
and
Development
Corporation
took
over
the
lease
from
MIT
and
has
since
purchased
the
machines
outright
from
IBM.
Since
the
wiring
associated
with
these
card
machines
has
been
thoroughly
checked,
checkout
of
the
Whirlwind
card
machine·
system
(C024)
should
be
a
fairly
straightforward
task
and
should
be
completed
around
August
15.
f.
Anelex
Alphanumeric
Printer
The
Anelex
Alphanumeric
Synchroprinter
used
with
Whirlwind
was
not
acquired
from
Lincoln
Laboratory
until
September,
1962.
As
the
task
of
reconnecting
computer
wires
and
cables
was
nearly
completed
at
that
point,
it
was
decided
to
defer
recabling
of
the
Anelex
printer
until
the
checkout
phase.
All
units
of
the
Anelex
printer
system
were
acquired
from
Linc9ln
with
the
exception
of
the
transition
panel
which
could
not
be
located
in
their
warehouse.
Thus,
it
was
necessary
to
build
a
new
transition
panel
and
27
this
task
(ME23)
was
com.pleted
on
April
11
of
this
year.
Recabling
of
the
Anelex
equipment
has
been
partially
completed
over
the
past
couple
of
months
as
time
permits.
Presently,
this
task
(ME24)
is
about
half
completed
and
is
scheduled
for
final
completion
on
August
9.
Operational
checkout
of
the
Anelex
system
will
be
accomplished
during
the
last
two
weeks
of
August
with
a
scheduled
date
of
August
30.
Here
again,
little
difficulty
is
anticipated
particularly
since
one
of
our
engineers
has
had
considerable
experience
with
the
operation
of
this
printer
at
MIT.
g.
Test
Control
Camera
Some
difficulties
wi~h
the
checkout
of
the
Test
Control
)
camera
subsystem
were
encountered
during
June
when
the
Test
Control
Display
Scopes
were
checked
out.
This
is
not
a
very'
complicated
system,
but
MITis
drawings
and
records
associated
with
this
system
are
in
very
poor
shape
and
apparently
a
few
wiring
errors
were
made
in
reconnecting
the
camera.
At
present,
the
camera
can
be
indexed
manually
but
not
by
program
command.
One
of
the
known
troubles
is
that
about
six
plug-in
units
are
missing
from
this
subsystem
and
were
missing,
according
to
our
records,
when
we
acquired
responsibility
for
the
computer.
Also,
because
of
the
poor
records
involved,
about
two
dozen
wires
will
have
to
be
traced
manually
before
the
cam.era
can
be
checked
out.
Since
this
is
a
relatively
low
priority
item,
it
has
been
deferred
until
the
first
week
of
September
and
this
task
(C027B)
is
scheduled
for
completion
on
September
4.
While
this
job
will
not
take
more
than
two
or
three
days,
the
amount
of
effort
is
out
of
proportion
relative
to
the
com-
plexity
of
the
system
due
to
the
poor
records
available.
h.
Magnetic
Drums
Checkout
of
the
Auxiliary
Drum
(C038)
is
scheduled
for
October
11
while
checkout
of
the
Buffer
Drum
(C039)
is
scheduled
for
November
8.
These
two
tasks
cannot
be
started
until
AC
and
DC
checkout
I
(C034,
C035, C036,
and
C037)
of
the
drum
bays
and
associated
input-output
equipment
is
completed.
It
is
somewhat
more
difficult
to
anticipate
what
troubles
may
be
encountered
in
checking
out
the
drums,
but
possible
trouble
sources
include
adjustment
and
alignment
of
read
and
write
heads,
cabling
errors
between
the
drums
and
the
main
computer,
troubles
with
the
electronic
chassis
in
the
drum
bays,
and
possible
difficulties
with
drum
bearings.
A
preliminary
check
of
the
condition
of
the
drum.
bearings
was
made
during
the
moving
and
reassembly
phase.
This
check
indicated
that
the
drum
bearings
are
in
good
shape
and
that
the
oil
leakage
problem.
was
due
to
over
filling
of
the
oil
reservoirs
~t
MIT.
Although
we
have
not
been
able
to
obtain
mechanical
assembly
drawings
for
the
drums
from
Sperry
Rand,
we
do
know
that
the
bearings
are
commercially
available.
We
have
also
been
advised
by
Sperry
Rand
that
the
run
down
time
from
full
speed
to
rest
when
power
is
removed
should
not
be
less
than
2-1/2
to
3
minutes
after
the
drum
has
been
running
for
one
hour.
A
shorter
run
down
time
would
indicate
bearing
troubles.
As
for
bearing
life,
Sperry
Rand
indicated
that
the
bearings
should
be
good
for
at
least
another
ten
years
on
the
basis
of
usage
to
date
by
MIT.
We
feel
that
our
present
schedule
makes
ample
provision
for
any
diffi-
culties
which
may
be
encountered
in
checking
out
the
drums.
i.
Teletype
Input
and
Output
Thorough
checking
of
teletype
input
and
output
subsystems
requires
a
teletype
transmitter
distributor,
a
typing
reperforator,
and
a
Type
28RO
teletypewriter.
Since
we
have
no
immediate
plans
for
use
of
these
sub-
systems,
we
will
be
able
to
check
out
only
those
portions
of
these
subsystems
which
can
be
checked
without
the
teletype
equipment
mentioned
above.
A
reasonably
thorough
check
of
the
electronics
can
be
made
by
means
of
the
Teletype
Test
Message
Generator
on
a
closed
loop
basis
with
a
computer
program.
and
this
type
of
checking
is
all
that
is
planned
for
the
accomplishment
of
events
C033
and
C040.
Checking
of
the
teletype
input
subsystem
which
uses
slots
on
the
buffer
drum
cannot
be
started
until
checkout
of
the
buffer
drum.
is
completed,
however.
28
'.
Event
No.
COl
C02
C03
C04
COS
C06
C07
C08
C09
COlO
COlI
COl2
COl3
COl4
COIS
C016
C017A
C017B
C018A
C018B
TABLE
3-1
Check
Out
(CO)
Desc
ription
Standby
Alternator
Cycling
to
Computer
Bus
AC
to
Computer
Racks
DC
Supplies
to
Computer
Busses
DC
to
Compute
r
Racks
Ma
rginal
Checking
System
Pulse
Generator,
Frequency
Divider,
and
Restorer
Pulse
Generator
Clock
Pulse
Control
Time
Pulse
Distributor
Test
Control
Synchronizers
Alarm
System
Control
Switch
Ope
ration
Matrix.
Control
Pulse
Output
Units
Program
Counter
Toggle
Switch
Storage
and
Parity
.
Register
Flip
Flop
Storage
Initial
Check
Arithmetic
Element
Final
Check
Arithmetic
Element
Initial
Che'ck
Core
Memory
Final
Check
Core
Memory
Date
Completed
or
Scheduled
December
19,
1962
December
19,
1962
January
21,
1963
February
28,
1963
April
30,
1963
February
28,
1963
February
28,
1963
February
28,
1963
February
28,
1963
May
10,
1963
March
15,
1963
March
15,
1963
March
15,
1963
April
23,
1963
April
22,
1963
May
16,
1963
May
16,
1963
July
30,
1963
June
4,
1963
July
3,
1963
29
Event
No.
C019
C020
C021
C022
C023
>:<
C024
>!<
C025
>!<
C026
C027A
>!<
C027B
C028
*
C029
>!<
C030
>:(
C031
C032
~:c
C033
>!<
C034
>!(
C035
>!<
C036
TABLE
3-1
Check
Out
(CO)
(Cont'd)
Description
In-Out
Element
Check
Register
Start
I/O
Equipment
Check
Flexowriter
Keyboard
Input,
Punch,
Reader
and
Printer
Photoelectric
Tape
Reader
IBM
Card
Machines
Anelex
Printer
Magnetic
Tape
Units
Test
Control
Displays
Test
Control
Camera
Intervention
and
Activate
Registers
Light
Guns
Indicato'r
Light
Registers
Display
Consoles
(3)
Real
Time
Clock
Teletype
Output
400A
Alternator
C'ycling
to
Bus
AC
to
I/O
Racks
DC
Supplies
to
I/O
Busses
Date
Completed
or
Scheduled
June
5,
1963
May
10,
1963
June
5,
1963
June
5,
1963
June
5,
1963
August
15,
1963
August
30,
1963
August
12,
1963
June
19,
1963
September
4,
1963
June
19,
1963
August
7,
1963
August
7,
1963
August
7,
1963
June
13,
1963
September
13)
1963
August
23,
1963
August
30,
1963
September
6,
1963
30
31
TABLE
3-1
Check
Out
(CO)
(Cont'd)
Date
Completed
Event
No.
De
sc
ription
or
Scheduled
*
DC
Supplies
to
1/0
Racks
1963
C03?
September
20,
~:c
C038
1963
Auxiliary
Drum
October
11"
):c
C039
Buffer
Drum
November
8,
1963
):c
~O40
Teletype
Input
November
15"
1963
*
Incomplete
as
of
July
31"
1963
IV
MAJOR
PROBLEMS
ENCOUNTERED
TO
DATE
During
the
checkout
phase,
we
have
encountered
several
major
problems.
Two
of
these,
namely
troubles
with
defective
wire-wound
resistors
and
phenolic
breakdowns
had
been
anticipated.
Two
other
difficulties,
one
with
slip
rings
on
the
400
amp
standby
alternator,
and
the
other,
troubles
with
the
air
conditioning
equipment,
occurred
unexpectedly.
We
felt
that
we
had
solved
the
wire-wound
resistor
problem
last
Summer
when
we
replaced
all
the
existing
8
watt
wire-
wound
resistors
in
the
computer,
but
unexpected
difficulties
were
encountered
with
these
new
res
istors.
Phenolic
breakdowns
did
not
occur
initially
and
for
several
months.
We
had
finally
reached
a
point
where
we
felt
the
problem
did
not
exi
st
when
a
rash
of
such
trouble
s
occurred.
Except
for
wire-wound
resistor
problems,
failure
rates
of
other
electronic
components
have
been
much
lower
than
we
had
anticipated.
In
particular,
vacuum
tube
failure
has
been
extremely
low
as
has
failure
of
crystal
diodes.
Relay
operation
has
also
been
excellent
and
we
have
encountered
trouble
with
only
one
relay
out
of
more
than
2000.
A.
Wire-Wound
Resistors
Tests
of
wire
-wound
resi
stors
at
Navy
Building
61
during
the
Summer
of
1961
indicated
a
need
for
replacing
all
such
resistors
in
the
computer
panels.
The
sample
tested
indicated
about
75%
of
these
resistors
had
opened
up
since
the
computer
was
shut
down
in
May,
1959.
During
the
Summer
of
1962,
new
military
RW3lG
ten
watt
wire-wound
resistors
were
purchased
to
replace
the
8
watt
resistors
in
the
computer
panels.
These
resistors
were
carefully
bridged
on
a
Wheatstone
Bridge
and
matched
to
within
10/0
tolerance
of
nominal
value
and
of
each
other
as
specified
in
Whirlwind
records.
Two
students
from
Wentworth
Institute
were
hired
for
the
Summer
and
were
assigned
the
task
of
replacing
these
resistors.
Although
MIT
had
replaced
some
6f
the
8
watt
resistors
with
12
watt
resistors
of
a
type
similar
to
that
which
we
purchased,
our
decision
to
purchase
10
watt
rather
than
12
watt
resistors
was
based
on
two
factors.
33
First,
the
10
watt
resistors
which
we
purchased
were
the
same
physical
size
as
the
8
watt
resistors
to
be
replaced,
whereas
the
12
watt
resistors
are
longer
and
present
some
mechanical
problems
in
:mounting.
Second,
it
was
known
that
12
watt
wire
-wound
resistors
were
a
standard
stock
item
at
Lincoln
Laboratory
and
were
therefore
easier
to
obtain
than
the
10
watt
resistors.
Although
it
was
obvious
that
10
watt
resistors
would
certainly
handle
the
power
dissipation
since
the
original
resistors
were
only
rated
at
8
watts,
we
did
compute
the
power
dissipation
in
these
resistors
and
found
that
the.
results,
namely
dis
sipations
ranging
from
2
to
4
watts,
confirmed
our
con-
clusions.
At
this
point
we
felt
that
we
had
solved
the
problem
and
due
to
other
urgent
tasks
we
assigned
the
resistor
replacement
job
to
the
Wentworth
students.
During
the
latter
part
of
the
Summer
of
1962·,
some
pulse
checking
was
done
on
the
Control
Element
and
the
resistors
which
had
been
replaced
here
seemed
to
give
very
satisfactory
performance.
However,
in
the
Spring
of
1963
while
checking
the
operation
of
the
Program
Counter,
difficulty
was
encountered
with
self-sustained
os
cillations
in
many
of
the
flip-flops
in
the
Program
Counter.
After
a
few
days
of
intensive
bench
testing
of
one
of
the
Program
Counter
panels,
and
review
of
early
MIT
records
and
memos
for
indications
of
such
troubles
in
the
past,
it
was
determined
that
the
cause
of
the
trouble
was
primarily
the
2000
ohm
10
watt
resistors.
Although
each
flip-flop
contains
two,
2000
ohm
resistors,
two
5000
ohm
resistors,
and
two
1600
ohm
resistors,
in
the
vast
majority
of
cases
proper
operation
of
flip-flops
with
voltage
margins
of
plus
or
minus
30
to
40
volts
has
been
accomplished
merely
by
replacing
the
2000
ohm
ten
watt
resistors
with
2000
ohm
twelve
watt
resistors.
Recently,
however,
it
has
been
neces
sary
to
change
the
1600
ohm
resistors
in
the
Accumu-
lator
Parital
Sum
flip-flops
and
the
B
-Register
flip-flops
to
obtain
proper
shifting
operations.
34
A
series
of
tests
on
ten
and
twelve
watt
wire
wound
resistors
run
by
the
manufacturer
at
our
request
revealed
the
probable
cause
of
the
problem.
These
tests
measured
the
resistance
and
inductance
of
both
ten
and
twelve
watt
resistors
at
l,
2
and
5
megacycles.
The
results
sho~ed
that
the
effective
AC
resistance
as
a
function
of
frequency
increased
much
faster
in
the
case
of
35
the
ten
watt
resistors
than
in
the
case
of
the
twelve
watt
resistors.
This
was
particularly
true
in
the
case
of
the
2000
ohm
resistors
and
the
trouble
is
assumed
to
be
due
to
the
smaller
wire
size
used
to
get
the
same
resistance
in
the
smaller
ten
watt
resistors.
While
most
computer
operations
are
performed
at
a
maximum
speed
of
1
megacycle,
shifting
in
the
Accumulator
and
B
-Register
is
done
at
2
'megacycles
and
thus
the
1600
ohm
resistors
also
had
to
be
replaced
.
,to
cure
this
latter
problem.
While
most
of
the
open
wire-wound
resistors
found
to
date
have
been
of
the
eight
watt
Navy-type,
there
have
been
other
instances
of
open
wire-wound
resistors.
Several
commercial
ten
watt,
non-inductive
wire-
wound
resistors
in
the
digit
plane
drivers
of
Core
Memory
Ban-ks
A
and
B
were
found
to
be
open,
and
one
22,
000
ohm,
twelve
watt
resistor'
used
in
a
cathode
follower
in
In-Out
Control
was
also
found
to
be
open.
Just
this
week,
trouble
developed
in
an
A-Register
panel
and
this
was
traced
to
an
open
2000
ohm
twelve
watt
resistor
which
had
been
installed
at
MIT
in
place
of
an
eight
watt
resistor.
Environmental
conditions
to
which
the
computer
was
subject
during
the
storage
period
are
felt
to
be
the
cause
of
open
wire
-wound
resis-
tors.
Since
the
computer
was
stored
in
unheated
space,
it
is
felt
that
the
low
temperatures
encountered
during
the
winter
months
caused
the
wire
to
become
brittle
and
that
contraction
of
the
wire
at
these
low
temperatures
caused
it
to
break.
B.
400
Amp
Standby
Alternator
Slip
'Rings
On
April
12,
after
nearly
two
months
of
trouble-free
operation,
difficulty
was
encountered
with
the
400
amp
standby
alternator.
This
trouble
was
evidenced
by
a
higher
than
normal
field
current
which
could
not
be
adjusted
downward
to
give
proper
operation.
Field
resistance
from
pole
to
pole
was
checked
and
found
to
be
additive
in
a
non-linear
fashion,
despite
the
fact
that
the
individual
pole
resistances
were
measured
to
be
two
ohms,
which
is
the
corr¢ct
value.
The
inescapable
colusion
was
that
somehow
additional
parallel
resistance
was
being
interposed
between
the
two
field
terminals.
Further
checking
revealed
that
the
screws
supporting
the
slip
rings
were
too
long
,and
nearly
shorted
the
slip
rings
together.
A
carbon
buildup
on
the
ends
of
these
screws
was
producing
a
twelve
ohm
resistance
between
the
slip
rings
with
the
field
disconnected.
The
screws
were
removed
and
replaced
with
shorter
ones
and
this
corrected
the
trouble.
While
the
long
screws
were
obviously
a
manufacturing
defect,
the
elapsed
time
meter
indicated
that
the
machine
had
run
for
some
17,
000
hours
prior
to
occurrence
of
this
trouble.
While
this
trouble
would
have
occurred
eventually,
its
onset
m.ay
have
been
hastened
by
an
accident
which
occurred
a
few
days
earlier
..
At
that
time,
it
was
noticed
that
power
was
being
applied
to
a
relay
as
sociated
with
the
magnetic
tape
racks.
When
the
filament,
switch
for
the
tape
racks
was
switched
to
what
was
thought
to
be
the
off
position
to
turn
off
this
relay,
two
No.
10
filament
wires
suddenly
burned
up.
.
When
this
switch
was
thrown,
it
effectivley
placed
a
36
short
across
the
output
of
the
400
amp
standbyalternator\
due'to
some
temporary
jumpers
which
had
been
installed
last
summer
and
which
had
not
been
removed.
'This
sudden
overload
on
the
alternator
burned
up
these
wires,
rather
than
blowing
the
600
amp
fuse
in
the
output
of
the
alternator.
Thu~,
this
accidental
overload
probably
hastened
the
breakdown
between
slip
rings.
Although
the
slip
ring
breakdown
was
in
the
;motor
exciter,
investigation
of
the
alternator
exciter
revealed
that
oversized
screws
had
been
used
there
as
well.
To
prevent
future
troubles,
the
screws
in
the
alternator
exciter
were
also
replaced
with
shorter
ones
at
that
time.
c.
Air
Conditioning
Equipment
Trouble
During
the
week
of
May
20
to
May
24
we
encountered
our
first
heat
wave
of
the
summer
season.
Twice
during
the
week
the
computer
shut
itself
down
as
a
result
of
excessive
temperature
in
the
vicinity
of
the
overheat
thermostat.
We
concluded,
at
first,
that
the
trouble
was
due
to
dirty
filters
in
the
liquid
line
which
were
causing
inefficient
ope
ration
of
the
air
conditioning
system.
On
May
24,
however,
the
air
conditioning
contractor,
who
had
installed
the
system,
came
to
replace
the
filter
elem.ents.
We
were
told
that
the
difficulty
was
due
to
a
nearly
complete
los
s
of
Freon
in
the
system..
Consequently,
the
system
had
to
be
completely
leak
checked
and
then
refilled
with
Freon
..
While
leak
checking,
a
few
small
leaks
were
found
and
corrected
and
it
was
concluded
that
the
Freon
loss
:must
have
occurred
over
a
long
period
of
ti:me
due
to
these
s:mall
leaks.
To
prevent
future
losses
of
such
proportion
l a
schedule
of
periodic
leak
checking
was
instituted.
Prior
to
the
Freon
loss
1
the
syste:m
was
shut
down
each
evening
l
:merely
by
turning
off
the
:main·
circuit
breaker
to
the
air
conditioning
syste:m.
After
replenishing
the
Freon
supply
1
this
procedure
resulted
in
severe
slugging
of
the
co:mpressors
with
liquid
Freon
during
the
night.
To
alleviate
this
slugging
proble:m
1
it
was
decided
to
let
the
syste:m
run
continuouslYI
even
though
unattended
l
since
it
is
:more
than
adequately
protected
with
fail-
safe
devices.
On
MondaYI
June
171
exactly
one
week
after
instituting
twenty-
four
hour
operation,
we
arrived
to
find
the
syste:m
shut
down
and
the
floor
covered
with
oil.
So:meti:me
during
the
week-end
the
nu:mber
4
co:mpressor
had
blown
a
flare
fitting
in
an
oil
line
which
resulted
in
co:mplete
loss
of
oil
in
the
entire
syste:m
and
very
possibly
si:multaneous
loss
of
a.
few
cylinders
of
Freon.
The
oil
fitting
was
replaced
and
fifty
gallons
of
Capella
oil
were
added
to
replenish
the
oil
supply.
Following
the
oil
loss,
twenty-four
hour
operation
of
the
air
conditioning
syste:m
was
abandoned
and
instead
the
syste:m
is
shut
down
each
evening
after
pu:mping
the
Freon
back
into
the
receiver
to
prevent
slugging
of
the
co:mpressors.
This
procedure
has
worked
reasonably
well,
but
this
was
not
the
end
of
our
air
conditioning
troubles.
During
a
heat
wave
at
the
end
of
June,
it
beca:me
obvious
that
the
air
conditioning
syste:m
was
still
not
operating
properly
and
the
co:mputer
again
shut
itself
off
due
to
overheating.
After
checking
several
possible
causes
of
the
trouble,
it
was
finally
concluded
that
additional
Freon
was
required.
More
careful
checking
revealed
that
we
had
replenished
only
half
the
original
supply
of
Freon
at
the
ti:me
of
the
loss
in
May.
Additional
Freon
was
added
to
bring
the
system
up
to
capacity
and,
in
addition,
the
cooling
coils
were
washed
down
and
several
adjust:ments
:made
to
the
syste:m.
These
:measures
have
resulted
in
excellent
operation
of
the
air
conditioning
syste:m
during
the
:month
of
July
and
particularly
during
the
excessively
hot
days
from.
Wednesday,
July
24
through
Friday,
July
26.
37
During
July
we
have
had
several
occassions
on
which
we
thought
additional
Freon
loss
might
have
occurred.
However,
thorough
leak
checkin~
and
subsequent
~fficient
operation
indicate
that
these
were
false
alarms.
The
most
recent
of
these
occassions
was
on'Monday,
July
29,
the
sixth
and
final
day
of
a
period
of
unseasonably
hot
weather.
Due
to
the
hot
weather
over
the
week-end
with
the
system
shut
down,
the
system
was
taxed
to
its
utmost
to
overcome
the
accumulated
heat
load
of
the
week-end,
without
the
additional
heat
load
of
the
compute
r.
Two
small
leaks
we
re
found
on
Monday
and
corrected,
but
low
Freon
indication
at
that
time
was
follo.wed
by
extremely
good
operation
on
Tuesday,
which
was
a
much
cooler
day.
Low
Freon
indica-
tion
on
Monday
is
now
felt
to
be
due
to
some
los
s
of
Freon
at
the
time
of
the
oil
leak
in
June,
which
means
that
two
or
three
cylinders
of
Freon
should
probably
be
added
to
bring
the
system
up
to
full
capacity.
D.
Phenolic
Breakdowns
Our
first
encounter
with
what
recent
experience
indicates
was
probably
a
phenolic
breakdown
occurred
on
May
20,
nearly
three
months
after
power
was
first
applied
to
the
computer
panels.
No
further
trouble
was
encountered
until
July
11,
when
we
encountered
the
first
of
six
phenolic
break-
downs
in
a
two
week
period,
four
of
which
occurred
in
one
panel.
The
phenolic
breakdown
problem
had
been
a
matter
of
considerable
concern
to
MIT
and,
as
mentioned
in
previous
progres
s
reports,
was
felt
by
us
to
be
a
major
difficulty
to
be
encountered
during
computer
checkout.
However,
since
nearly
five
months
of
continuous
power
application
had
elapsed
since
turning
on
the
computer
with
only
one
possible
phenolic
breakdown,
we
had
thought
that
this
would
not
be
a
serious
problem.
However,
recent
experience
has
reversed
our
thinking
on
this
problem
and
we
now
feel
that
phenolic
breakdown
may
be
a
serious
difficulty
which
may
increase
in
frequency
as
time
goes
on.
Investigation
of
this
problem.
during
July
has
resulted
in
the
con-
clusion,
however,
that
the
phenolic
breakdown
problem
is
nota
disastrous
one
because
there
is
a
relatively
inexpensive
solution.
The
conclusion
that
this
problem
is
tending
to
increase
in
frequency
is
based
on
a
fairly
thorough
search
of
MIT
r s
records
which
failed
to
reveal
any
two
week
period
in
which
as
many,
as
six
breakdowns
occurred.
Our
investigation
generally
concurs
with
38
earlier
investigation
by
MIT
which
indicated
that
phenolic
breakdown
is
due
to
silver
migration
and
that
this
is
predominantly
a
surface
effect.
The
first
four
breakdowns
we
encountered
in
July
on
one
panel
occurred
on
the
component
side
of
the
phenolic
and
tended
to
confirrrl
an
MIT
opinion
that
cool
air
heavily
saturated
with
moisture
at
the
air
duct
outlet
was
a
major
contributing
factor.
MIT
records
on
this
particular
panel
reveal
about
a
half
dozen
previous
break-
downs,
whereas
records
on
an
identical
panel
at
the
top
of
the
same
rack
show
that
no
breakdowns
have
ever
occurred.
Consequently,
the
flow
of
cold
air
to
the
component
side
of
this
panel
was
blocked
and
no
further
breakdowns
have
.
occurred.
39
We
feel,
on
the
basis
of
the
two
more
recent
breakdowns,
however,
that
cool
air
laden
with
moisture
may
not
be
as
important
a
factor
as
we
had
originally
thought.
The
two
latter
cases
occurred
on
the
back
side
of
the
phenolic
board
in
panels
which
were
remotely
located
from
the
cool
air
ducts.
The
latter
of
these
two
panels,
B
-Register
digit
15,
was
removed
from
the
computer
and
examined
closely.
After
removing
the
phenolic
board
from
the
aluminum
panel
it
was
evident
that
several
potential
trouble
spots
existed
which
werel.n.ot.
in
evidence
on
the
component
side
of
the
phenolic.
Both
sides
of
the
phenolic
panel
are
covered
with
dirt
which
is
probably
soot
from
Cambridge
and
a
film
whose
composition
is
unknown.
Cleaning
with
a
good
solvent
removes
both
the
soot
and
the
film
as
well
as
deposits
of
silver,
and
in
areas
where
breakdown
has
occurred,
cleaning
of
the
surface
appears
to
restore
the
insulation
resis-
tance
of
the
phenolic.
Cleaning
is
a
ve
ry
tedious
task
when
done
manually
due
to
the
necessity
for
opening
up
the
panel
and
the
complex
layout
of
components
and
wires.
Thought
was
given,
therefore,
to
cleaning
in
an
ultrasonic
bath,
but
pricing
of
this
procedure
reveals
it
to
be
extremely
expensive
and
cleaning
of
all
computer
panels
would
be
costly
in
terms
of
time
as
well.
Furthermore,
MIT's
chemical
analysis
revealed
that
some.
silver
migration
occurs
within
the
phenolic
material
itself,
although
to
a
considerably
lesser
degree.
Since
cleaning
is
an
expensive
process,
and
since
body
migration
would
not
be
cured
by
cleaning,
consideration
was
given
to
c;t
more
effective
way
of
eliminating
the
problem
entirely.
MITts
solution
of
correcting
each
breakdown
as
it
occurs
by
replacing
one
of
the
affected
lugs
with
an
insulated
standoff
lug
is
acceptable
provided
the
frequency
of
occurrence
does
not
increase.
Phenolic
breakdown
can
be
located
and
corrected
quickly
by
this
:means
without
excessive
COIllputer
down
ti:me.
However)
if
the
frequency
increases
a
Illore
effective
solution
is
required.
ExaIllination
of
the
panel
taken
from
B
-Register
digit
15
revealed
that
the
probleIll
exists
only
between
terIllinals
having
a
relatively
high
potential
difference
in
the
order
of
150
to
250
volts.
Thus)
a
solution
which
effectively
inhibits
Illigration
between
such
terIllinal
pairs
will
eliIllinate
the
probleIll.
After
further
consideration)
it
was
concluded
that
the
IllOSt
effective
and
siIllplest
:method
for
eliIllinating
Illigration
between
these
terIllinal
pairs
is
to
cut
a
slot
in
the
phenolic
board
between
these
terIllinals
thus
iIllposing
an
air
gap
between
them.
While
this
in
itself
would
be
a
fairly
tiIlle
consuIlling
task)
it
is
felt
to
be
the
fastest,
:most
effective)
and
least
expensive
solution.
While
there
are
sOIllewhere
in
the
order
of
170
panels
affected
by
this
probleIll,
there
are
only
about
35
different
types
of
panels.
Thus,
it
would
be
a
fairly
reasonable
task
to
check
the
asseIllbly
drawings
for
each
of
these
panel
type
s,
locate
all
potential
trouble
spots,
and
then
proceed
to
cut
air
gaps
between
all
potentially
troublesome
terminal
pairs
in
all
panels.
This
task)
which
Illight
require
in
the
order
of
one
or
two
weeks
of
cOIllputer
shutdown,
will
be
instituted
if
it
becomes
necessary
due
to
a
sharp
increase
in
the
frequency
of
occurrence
of
phenolic
breakdowns.
In
the
meantime)
however)
we
plan
to
follow
MITts
procedure
of
correcting
each
trouble
as
it
occurs.
E.
Power
Failures
Two
outside
power
failures
have
occurred
during
the
checkout
40
period.
The
first
of
these
occurred
on
May
20
when
some
of
Boston
Edison's
underground
power
lines
were
flooded
in
Maynard.
The
second
failure
occurred
on
July
18
when
lightning
struck
a
Boston
Edison
substation
in
Burlington)
Massachusetts.
On
both
occassions
the
computer
under-voltage
sensing
mechanism
worked
correctly
and
cycled
the
computer
down
in
the
proper
fashion.
Both
of
these
failures
were
external
to
the
building
and
were
due
to
circum-
stances
beyond
ourco,ntrol.
Such
failures
cause
a
certain
amount
of
incon-
venience
and
delay
as
they
did
at
Cambridge.
This
problem
could
be
eliminated
by
the
installation
of
diesel
generators,
but
this
is
an
expensive
solution
to
be
resorted
to
only
if
the
priority
of
future
work
demands
it.
No
action
on
this
matter
is
contemplated
at
the
present
time
and
this
subject
is
mentioned
here
only
for
the
purpose
of
documenting
a
major
trouble
encountered
during
checkout.
Another
reason
for
including
it
here
is
to
emphasize
the
fact
that
to
date
no
~nternal
power
failures
have
occurred.
41
V
SUMMARY
This
progress
report
describes,
in
some
detail,
the
moving,
reassem-
bling,
and
checkout
of
the
Whirlwind
I
computer
from
the
commencement
of
its
move
from
Navy
Building
61
in
South
Boston
on
December
6,
1961
until
the
present.
Also
presented
are
our
plans
for
completing
the
checkout
of
the
computer
by
November
15,
1963.
PERT
networks
showing
the
events
of
the
moving
and
reassembly
phase
and
the
checkout
phase,
their
interrelationships
and
completion
dates
are
presented
and
described.
To
date
this
project
has
encountered
several
major
problems,
some
of
which
were
expected
while
others
were
unexpected.
These
problems
have
been
described
as
have
their
solutions.
Solutions
to
all
problems
have
been
effected
with
the
exception
of
that
for
the
phenolic
breakdown
problem
and
this
will
be
effected
when
and
as
required.
No
further
major
problems
are
anticipated
but
if
new
ones
should
occur,
they
are
not
expected
to
be
insurmountable.
Thus,
we
feel
that
successful
completion
of
checkout
will
be
accomplished
on
November
15,
1963.
42
