Digital Equipment PDP-8/A Operator's Handbook Manual
EK-SA001-0P-002
PDP-Sf
A OPERATOR'S
HANDBOOK
digital
equipment
corporation • maynard. massachusetts
PDP;;;8/ A
OPERATOR'S
HANDBOOK
digital
equipment
corporation
• maynard. massachusetts
18t
Edition, September 1975
2nd Printing (Rev),
September 1976
Copyright
© 1975, 1976
by
Digital Equipment Corporation
The material in this manual
is
for informational
purposes and
is
subject to change without notice.
Digital Equipment Corporation assumes no responsibility for any errors which may appear in this
manual.
Printed in U.S.A.
This document
was
set
on
DIGITAL's DECset-8000
computerized typesetting system.
The following are trademarks
of
Digital Equipment
Corporation, Maynard, Massachusetts:
DEC
FLIP CIllP
DIGITAL
UNIBUS
DEC
US
PDP
FOCAL
COMPUTER LAB
MASSBUS
CONTENTS
Page
CHAPTER 1
CHAPTER
2.1
2.2
2.2.1
2.2.2
CHAPTER 3
3.1
3.2
2
3.3
3.4
3.4.1
3.4.2
3.4.3
3.4.5
3.4.6
3.4.7
3.4.8
3.4.9
3.4.10
3.4.11
INTRODUCfION
PACKING AND UNPACKING INSTRUCTIONS
UNPACKING INSTRUCTIONS
PACKING INSTRUCTIONS
BA8-C Chassis Assembly
Other
PDP-8/A Chassis Assemblies
SYSTEM DESCRIPTION
GENERAL
CHASSIS DESCRIPTIONS . . . . . . . . . . . . . . . . . . . .
EXPANSION TECHNIQUES . . . . . . . . . . . . . . . . . . . .
PDP-8/ A MODULE DESCRIPTIONS
KK8-A Central
MS8-A Read/Write Random Access Memory
MR8-A
NHvI8-AA
MM8-AB 16K Core Memory . . . . . . . .
DKC8-AA
K~M8=A
Semiconductor Memory
Core Memory
Limited Function
KC8-AA
.......
Processor Unit (CPU)
Read-Only Random Access Memory (ROM)
8K Core Memory . . . . . . . . . . . . . . 3-15
I/O Option Board
Extended Option Board
Power Supply Regulator
Panel
Programmer's Console
.....
. . . . . . . . . . . . . . . . . . . .
.....................
..................
(RAM)
.......
....
Power Supply . . . . . . . . . . 3-25
...................
........
...
..........
..........
......
.
....
. . . . .
...........
. . . . . . . . . . . 3-30
....
.
....
..
..
..
2-1
2-1
2-1
2-3
3-1
3-4
3-8
3-9
3-9
3-11
3-12
3-16
3-18
3-22
3-26
3-29
CHAPTER
4.1
4.2
CHAPTERS
5.1
5.2
4
5.3
5.4
CHAPTER
6.1
6.2
6
6.3
6.4
CHAPTER
7.1
7
INSTALLATION AND INITIAL POWER TURN-ON
ENVIRONMENTAL AND
INITIAL POWER TURN-ON
TESTING PDP-8/A WITHOUT PAPER TAPE DIAGNOSTICS
PROGRAMMER'S CONSOLE
CENTRAL PROCESSOR TEST ROUTINES
ENTERING TEST ROUTINES FROM PROGRAMMER'S CONSOLE
CENTRAL PROCESSOR TEST ROUTINES . . . . . . . . . . . .
LOADING THE RIM AND BINARY
LOADING
CHECKING THE RIM
LOADING THE BINARY LOADER
LOADING BINARY
TESTING THE PDP-8/A USING MAINDEC DIAGNOSTIC PROGRAMS
CENTRAL PROCESSOR UNIT (CPU) TEST
RIM LOADER
POWER REQUIREMENTS
............
........................
LOADERS
..........
LOADER
FORMATIEDPAPER
.......
.....
iii
.................
.
.
.
TAPES
.
....
. . . . . .
..
..
..
4-1
4-1
5-1
5-1
5-1
5-2
6-1
6-2
6-2
6-3
7-1
CHAPTER 8
S.l
S.2
S.3
S.4
CONTENTS (Cont)
ADDITIONAL DIAGNOSTIC TESTS
MEMORY TEST
.........
.
DKCS-AA TEST . . . . . . . . . . .
KMS-A
EXTENDED OPTION BOARD TEST
TESTING
EXTENDED MEMORIES
CHAPTER 9 BASIC PDP-8/A MAINTENANCE
APPENDIX A INSTRUCTION SUMMARY
APPENDIX
B DOCUMENTATION
APPENDIX
C WARRANTY AND MAINTENANCE SERVICES
APPENDIX
D
OMNmus
LOADING
APPENDIX
E POWER CONNECTION
Figure No.
2-1
2-2
2-3
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-S
3-9
3-10
3-11
3-12
3-13
3-14
3-15
3-16
3-17
3-1S
ILLUSTRATIONS
Title
SA420, SA620, SAS20 Packaging .
PDP-S/A Computer Packaging (Inner)
PDP-S/A Computer Packaging (Outer)
PDP-8/A
Computer
........
.
Part
of
MS320 Module Showing R55, Which is Removed for SA Operation
PDP-8/A Semiconductor
Chassis
..........
.
PDP-8/A Semiconductor Computer Chassis Dimensions
SA Chassis - H9300 (Transformer Cover Removed)
SA620 Chassis . . . . . . . . . . . . . .
SA420/SA620/SAS20 Chassis Dimensions
SA600/SA620 Expansion
.......
.
KKS-A (MS315) CPU Module
.....
.
MSS-A (MS311) Read/Write Random Access Memory
MRS-A (MS312) Read Only Memory (ROM)
MMS-AA SK
Core Memory
.....
MMS-AB
16K Core Memory . . . .
'.
. . . .
DKC8-AA
(MS316) I/O Option Board
D
Etch
Revision
of
DKCS-AA
(MS3l6)
I/O Option Board
KMS-A (MS317) Extended Option Board
.....
Semiconductor Memory Regulator Board (GS016)
SA Master/Slave Switch
.............
.
iv
Page
S-l
S-2
S-6
S-9
Page
2-2
2-4
2-5
3-1
3-3
3-4
3-5
3-6
3-7
3-S
3-9
· 3-10
·
3-11
· 3-13
· 3-15
3-17
·
3-18
· 3-19
..
3-20
3-25
· 3-27
Figure No.
3-19
3-20
3-21
6-1
6-2
E-l
Table No.
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
3-11
3-12
3-13
3-14
8-1
8-2
9-1
ILLUSTRA
nONS
(Cont)
Title
Core Memory Regulator Board
(G8018)
Limited Function Panel
.....
KC8-AA Programmer's Console
Paper Tape Leader
.......
.
LT33 Teletype Controls
.....
.
PDP-8/ A Electrical Connection
TABLES
Title
PDP-8/ A Computer Assemblies . . . . . . . . . .
PDP-8/ A Computers, Dedicated
Omnibus Slots
....
KK8-A (M8315) Central Processor Unit Switch Settings
MS8-A Read/Write Memory Switch Settings
MR8-A Read
Only Memory Switch
SettLl1gs
. . .
MM8-AA 8K Core Memory Jumper Installation
..
. . . . .
MM8-AB
16K Core Memory Jumper Installation
DKC8-AA
I/O
Option Board Switch Settings, C-Etch Module
DKC8-AA
Option Board Switch Settings, D-Etch Module . .
Auto-Restart Select Switch Settings
..
. . . . . . . . . . .
Bootstrap Select Switch Settings for ROMs Labeled 87 A2 and 88A2
Page
· 3-28
· 3-29
· 3-30
6-2
6-3
E-l
Page
3-2
3-3
· 3-10
..
3-12
·
..
3-14
.....
3-16
·
..
3-16
· 3-20
.....
3-21
..
3-23
· 3-23
· 3-23
·
..
3-24
Bootstrap Select Switch Settings for ROMs Labeled 158A2 and 159 A2
Bootstrap Select Switch Settings for ROMs Labeled 156A2 and 157 A2
Bootstrap/Auto-Restart Switch Settings . . . . . . . . . . . .
.....
Bootstrap Switch Settings for ROMs Labeled
87
A2 and 88A2 (E82 and E87)
Bootstrap Switch Settings for ROMs (E82 and E87) Labeled 158A2 and 159A2
3-24
8-8
8-8
9-1
Basic PDP-8/ A Troubleshooting
.......................
.
v
CHAPTER 1
INTRODUCTION
There are two basic types
of
computers in the PDP-8/ A family. The first type
is
the
PDP-8/
A, which uses
semiconductor memories (MS8 and MR8). The second type
is
represented by a series
of
computers, each
of
which uses 8K or
16K
core memory (MM8); this series consists
of
the 8A400, 8A420, 8A600, 8A620, 8A800, and
8A820 computers. When a reference applies to both types
of
computers, the designation
"PDP-8/
A"
is
used.
"PDP-8/A
semiconductor" refers to the semiconductor memory computer, while "8A400," for example, refers
to a specific core memory machine and
"8A"
refers to the core memory machines in general.
The
PDP-8fA
Operator's Handbook includes instructions for packing, unpacking, and installing a PDP-8/A
miniprocessor. All computers and modules are tested thoroughly at DIGITAL's manufacturing facilities before
they are shipped. However, many switches and jumper wires can be arranged
by
the customer for specific pur-
poses; furthermore, there
is
a need both to verify system interconnections and site preparations, and to detect
possible hidden damage incurred during shipping. Consequently, a number
of
initial operating tests are also
included in this handbook.
A
PD
P-8
/ A basic system can comprise a variety
of
components. The following three basic systems are the most
common:
1.
A basic PDP-8/ A, * a memory, and a Limited Function Panel. (This computer does not include a KM8
Extended Memory
Option module and, hence, must be a PDP-8/ A semiconductor.)
2.
A basic PDP-8/ A, a memory, a Limited Function Panel, a KM8 Extended Memory Option module,
a DKC8-AA
I/O
Option module, and a Programmer's Console. (Chapter 5 describes operating tests
for this arrangement.)
3.
A basic system as described in
2,
but accompanied by a teletypewriter and diagnostic** programs.
(Chapter 7 describes operating tests for this arrangement.)
*A
basic PDP-8fA
is
defmed as a Central Processor Unit (CPU) and a chassis assembly (chassis, Omnibus, and power supply).
**Diagnostics are test programs written
to
fmd faults
in
the logic. The PDP-8fA programs are supplied
on
paper tape. Diagnostic pro-
grams are optional and may be ordered from
the
Software Distnoution Center, 146 Main St., Maynard,
MA,
01754.
1-1
2.1
UNPACKING
INSTRUCfIONS
CHAPTER 2
PACKING AND UNPACKING
INSTRUCTIONS
All PDP-8
fA
computers are packaged in two containers; the inner container holds the computer and some kind
of
protective material.
The
steps
in
this section
are
sufficiently general
to
apply to any PDP-8f A.
To
unpack the PDP-8f A computer, proceed as follows.
i.
Open the outer carton and remove the inner carton.
2.
Open the inner carton.
3.
Carefully remove the cardboard from the top and sides
of
the computer.
4.
Carefully remove the computer from the box.
5.
Inspect the computer for damage.
If
the computer
is
damaged, notify the carrier immediately.
6.
Unpack any other boxes included in the shipment.
7.
Check that all equipment, software, manuals, etc., are present as specified on the shipping list inside
the carton.
8.
Save the cartons
and
packing material
to
use if the PDP-8f A is later repacked.
9.
Refer
to
Chapter 4 for PDP-8f A installation procedures.
2.2 PACKING INSTRUCTIONS
Two types
of
packages are used for the PDP-8f A computers. The type used and the applicable packing instruc-
tions depend on the type
of
PDP-8f A chassis assembly.
2.2.1 BA8-C Chassis Assembly
The 8A420, 8A620, and 8A820 computers use a BA8-C chassis assembly (20-slot Omnibus). Figure
2-1
illustrates
the packing procedure. The computer
is
first placed in the inner container (9905417), the empty space
is
filled
with plastic protective material
(AIR
CAP, SD-120), and the container
is
sealed.
The
sealed inner container
is
surrounded with protective foam material which
is
then enclosed by the two telescope caps. Finally, the package
is
secured by two plastic straps.
2-1
FULL
TELESCOPE
CAP
(9905647)
FOAM
PAD
(9905648)
PACKAGED
OPTION
IN BOX
(9905417)
FULL
TELESCOPE CAP
(9905647)
Figure
2-1
8A420, 8A620, 8A820 Packaging
2-2
FILL
VOIDS I N CARTON
WITH
AIR
CAP
SD-120
FOAM CORRUGATED
SIDE
WALL
ASS'Y
(9905641
)
ust:
(2)
PLASTIC
STRAPS
(1)
IN
EACH
DIRECTION
TO HOLD CONTAINER
TOGETHER.
08-1789
2.2.2 Other
PDP-8/
A Chassis Assemblies
CAUTION
The G8016 Regulator Board assembly used on
PDP-8/A
semiconductor computers contains a battery. This battery,
while not
of
sufficient t'oltage to cause electrical shock,
represents a possible hazard
if
shorted.
If
repacking this
type computer, ensure that there is
no
loose metal, such as
solder, wire, or sheet metal parts, inside the cabinet.
The PDP-8f A semiconductor computer and the 8A400, 8A600,
and
8A800 computers use a chassis assembly
that
has a
lO-s10t
or
12-s10t
Omnibus.
To
pack these computers, proceed as follows.
1.
Place the computer in the smaller
of
the two shipping cartons with the back (side with power cord)
of
the computer against the side
of
the carton.
2.
Place the beveled die-cut sheet with foam protector (part number
9905675)
in front
of
the computer
(Figure 2-2).
If
the Limited Function Panel
and
a pop panel are
on
the computer, the beveled edge
should be down inside the carton.
If
the computer has a Programmer's Console, the beveled edge
should be up
so
that
the cut-out in the cardboard fits the Programmer's Console.
3.
Place the die-cut sheet with foam saddle (part number
9905677)
downward over
the
computer.
The
end with two pieces
of
foam should be fitted around the fans and the other end should be positioned
so that the cardboard fits behind the cabinet mounting flange and the foam
is
against the side
of
the
carton.
4.
Close the flaps and seal the carton with tape.
5.
Surround the sealed carton with protective foam material and enclose with telescope caps (Figure
2-
3).
6.
Strap in both directions using steel
or
plastic strapping.
2-3
DIE
-CUT
WITH FOAM BEZEL
SHEETS
PROTECTOR
(9905675J
DIE-CUT SHEET
WITH
FOAM
(9905667]
SADDLE
Figure 2-2 PDP-8f A Computer Packaging (Inner)
REGULAR SLOTTED
CARTON
(9905649)
08-1494
2-4
FULL
TELESCOPE
CAP
(9905662)
FOAM
PAD
(9905663)
PACKAGED
OPTION
IN BOX
(9905649)
FOAM
PAD
(9905663)
FOAM CORRUGATED
SIDE
WALL
ASS'Y
~
(9905661)
~
Figure
2-3
PDP-8f A Computer Packaging (Outer)
,
2-5
08-1790
CHAPTER 3
SYSTEM DESCRIPTION
3.1
GENERAL
A
PDP-8/
bottom with three switches and three indicators) and the Programmer's Console. The Programmer's Console can
be located remotely from the chassis; in such a case,
is
attached instead. Both the panel
them
panels
A computer
off
the latches.
are
removed, the module boards
is
pictured in Figure 3-1, which shows
(Do
not
both
the Limited Function Panel (the panel on the
or
when the system does not include a console, a blank panel
and
the console are latched to the chassis; they can be removed by pulling
pull too vigorously; the panels are attached by cables to interior points.) When the
are
visible.
Figure
3-1
PDP-8/A
3-1
7288-5
Computer
The
PDP-SI
A computers have three different mechanical assemblies
that
can be characterized by
the
number
of
available Omnibus slots;
that
is, the
PDP-SI
A semiconductor
computer
assembly
has
a IO-slot Omnibus, while
the
SA
computer assemblies have either a 12-slot
or
a 20-slot Omnibus. Table
3-1
relates the various PDP-S I A
computers
to
some
of
the basic system components.
Note
that
the
SA400 can be considered to be the basic SA
computer,
having a core memory,
an
SA
CPU,
and
a 12-slot Omnibus. Thus,
the
SA420 differs only in
that
it has
a
20-slot Omnibus; the SA600 differs in
that
it has a
PDP-S/E
CPU;
the
SA620 differs in
that
it has a
PDP-S/E
CPU
and
a 20-s10t Omnibus; the
SASOO
differs
in
that
it
has
an
FPP-SA
(not
indicated in Table 3-1);
and,
the
SAS20 differs in
that
it has an FPP-SA
and
a 20-s10t Omnibus. Also, note
that
only the
SA
computers
that
use a
PDP-S/E
CPU
can be expanded.
Table
3-1
PDP-8fA Computer Assemblies
Computer
CPU
Memory *
Basic Power Assembly
Omnibus
Expandable ?
PDP-8fA
KK8-A
Semiconductor
H763 H9192
(1
O-sIot)
No
8A400
KK8-A
Core
H9300
H9194 (12-s10t)
No
8A420
KK8-A
Core
BA8-C
H9195 (20-slot)
No
8A600
KK8-E
Core
H9300 H9194 (12-slot)
Yes -as
many
as
20
slots can
be
added
8A620
KK8-E
Core
BA8-C
H9195 (20-slot)
Yes -as
many
as
20
slots can
be
added
8A800
KK8-A
Core
H9300
H9194 (12-slot)
No
8A820
KK8-A
Core
BA8-C
H9195 (20-slot)
No
* A
KMS-A
(or
KMS-E)
Extended Memory Option module must
be
included
in
all the
SA
computers, since their basic memory capacity
is
SK
or 16K; the
KMS
is
optional with the PDP-Sf A semiconductor computer, since the basic memory capacity can be less than,
greater than, or equal to 4K.
In addition to the
CPU,
most
DIGITAL
PDP-S/E
options
will
operate
with the
PDP-S/A
computers. The
following will not:
1.
KPS-E Power
Faill
Auto-Restart
option
2.
DKS-EA Line Frequence Real-Time Clock
option
3.
MMS-E
4K
Core
Memory
4. MMS-EJ SK
Core
Memory
The
KES-E
option
(Extended Arithmetic Element)
and
the
TDS-E
DECtape
Control
will
operate
only with the
SA600 and SA620 computers.
Moduies
can
be inserted in almost any
PDP-SI
A Omnibus slot. There are, however, some restrictions
and
these
are summarized in Table 3-2.
Notice
that
an MS320 module (Bus Loads)
is
inserted in slot 1
of
the
SA600
and
SA620 computers. This module
must be modified before it can be used in the
SA600 and SA620 computers.
If
the modification has been accom-
plished, R55 (Figure 3-2) will have been removed;
if
R55 is present, carry
out
the procedure outlined in
DEC
ECO
MS320-00007.
3-2
Table 3-2
PDP-Sf A Computers, Dedicated Omnibus Slots
PDP-8/ A Semiconductor,
Omnibus Slot SA600 SA600 + KES-E SA620
SA620
+ KES-E
SA400, SA420,
SASOO,
SAS20
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
IS
19
20
NOTES:
I
M8320
M8316
M8317
I
I
I
M8300
I
M8310
M8330
M8320
I
M8316
M8317
I
M8300
M8310
M8341
M8340
I
M8330
I
M8320
M8316
M8317
MS300
MS310
MS330
M8320
M8316
M8317
MS300
MS310
MS341
MS340
MS330
I
I
I
I
1. MS316 and MS317 are interchangeable in slots 2 and 3.
2. Module numbers are related
to
options as follows:
MS315
MS316
MS317
MS320
MS300 }
MS310
MS330
CPU
(KKS-A)
I/O Option Board (DKCS-AA)
Extended Option Board (KMS-A)
Bus Loads
I
CPU
KKS-E
Timing Generator
KKS-E
08
-1785
Figure
3-2
Part
of
M8320 Module Showing R55,
Which
is
Removed for 8A Operation
3-3
M8315
M8316
M8317
3.2 CHASSIS DESCRIPTIONS
Three chassis types are available. The
PDP-8/
A semiconductor computer chassis
is
illustrated in Figure 3-3. (The
front panels have been removed.) Modules are inserted in the Omnibus from the front
of
the unit. Both quad-and
hex-size modules can be inserted;
the
fingers
on
connectors E
and F of
the hex size modules do
not
carry
Omnibus signals. (Some hex modules
do
not
have connectors E
and
F.) Figure 3-4 illustrates the dimensions
of
the same computer, as well as indicating the ac line
and
fuse locations.
G8016
REGULATOR
ASSEMBLY
POWER
CONTROL
FUSE
MASTER-SLAVE
SWITCH
Figure 3-3 PDP-8 / A Semiconductor Chassis
3-4
LIMITED
FUNCTION
PANEL
7.2884
'\9
in.
l48.
26cm)
NOTE:
applied
ac
power
If
you
advised
1.
2.
3.
This
circuit
to
the
OMNIBUS.
from
the
are servicing
breaker
power
the
controls
It
does
transformer
power
supply,
not
to:
Turn PDP-8/A
off.
Unplug the power cord.
Remove metal jewelry that could short
the battery, heat up, and
cause
burns.
Figure 3-4 PDP-8f A Semiconductor Computer Chassis Dimensions
dc power
remove
or
fans.
you
are
4A(110V
OPERATION)
(220V
OPERATION)
SLOW
BLOW
08-1146
OR
FUSE
2A
3-5
Figure 3-5 shows the chassis
that
is
used with
the
8A400, 8A600, and 8A800 computers. The dimensions are the
same as the
PDP-8/
A semiconductor chassis; interior components
are
different.
The
08018
Regulator Board
assembly has been removed to show the connector in which
the
assembly is inserted. The Omnibus connector
blocks in the connector
HE" position are needed
to
accommodate the E connector
of
the core memory modules.
REGULATOR
BOARD
SLOT
POWER
CONTROL
FUSE
CORE
MEMORY
SLOTS
CABLE
TO CONNECT
LIMITED
FUNCTION
PANEl
Figure 3-5 8A Chassis - H9300 (Transformer Cover Removed)
3-6
7367-3
Figure
3-6
shows the chassis used with the 8A420, 8A620, and 8A820 computers. The example shown
is
an
8A620, containing the KK8-E
CPU
and Timing Generator
and
the Bus Loads module. The H9195 Omnibus
is
mounted on the center wall assembly (DEC
Part
Number
70-12561); modules are inserted from the front
of
the
unit. Two G8018 Regulator Board assemblies are contained in the rear
of
the chassis; the regulator boards are
inserted in
PC board slots
that
are mounted on the rear
of
the center wall assembly. Figure 3-7
is
an outline
drawing that gives the chassis dimensions
and
illustrates the placement
of
the G8018 assembly.
7996-2
Figure 3-6 8A620 Chassis
3-7
(BElWEEN
1831
in.
(46.50 em.)
~OUNTING
HOLE
CENTER~
~
T
10.44
in.
(26.52: em)
1
~
~~~
8.42
e,".)
~
Figure 3-7 SA420 /SA620 /SAS20 Chassis Dimensions
3.3 EXPANSION TECHNIQUES
Table
3-1
noted
that
the SA600
added to the basic chassis, increasing the system capacity accordingly. Figure
the expansion possibilities available for each type.
The basic chassis
bottom
chassis. The
appropriate
MS300, MS310, and MS330 modules in Omnibus slots IS,
includes a
Omnibus slots
slot
is
connected to the expander chassis by a ribbon cable.
of
the basic chassis (slot
MS300, MS310, and MS330 modules must
Omnibus slots
KES-E option, this, too, must be removed from the basic chassis
of
the expander.
and
of
the
expander chassis, e.g.,
SA620 computers could be expanded. Either a BAS-C
3-S
illustrates the basic chassis and
One
cable connector
12
or
slot 20), the
other
connector
be
removed from the basic chassis
if
expanding an SA600 with a BAS-C chassis, insert the
19,
and 20, respectively,
3-S
is
inserted into slot 1
of
the BAS-C.
and
inserted in the appropriate
08
-1788
or
an H9300 can be
is
inserted into the
of
the expander
and
placed in the
If
the computer
SA600
(KKS-E)
H9300
I
L_-,
I
BORB
NOTE:
SA620
(KKS-E)
BAS-C
Remove
CPU
modules from basic chassis and place them in expander chassis,
leaving bus loads in
slot 1 of
basic chassis.
Figure 3-8 8A600 /8A620 Expansion
3.4
PDP-8f
A
MODULE
DESCRIPTIONS
08
-1786
The major units
that
constitute a
PDP-8/
A are described in
the
following paragraphs, along with
the
module
switch settings. The most common switch settings
are
enclosed in boxes for easy identification.
CAUTION
Switch settings may be accidently changed unless modules
are removed and inserted carefully.
3.4.1
KKS-A Central Processor Unit
(CPU)
The KK8-A, shown in Figure 3-9,
is
a multilayer hex module (M8315) which resides in the
top
slot
of
the
Omnibus. The KK8-A has an Auto-Start feature, which
is
used to start
the
computer automatically when power
is
turned on.
If
you
are
not
using the
CPU
Auto-Start feature,
turn
switch SI-7
ON
and
switches SI-1
through
S1-6
and
SI-
8
OFF.
If
you are using
the
CPU
Auto-Start feature, set switch-
es
as shown in Table 3-3.
CAUTION
The direction
of
motion
of
the switch activating lever (slide
or rocker) varies with the switch manufacturer. Always
look for a printed
ON
on
the switch assembly.
If
there is
no
ON indication, look for a black dot on the rocker.
Depressing the end
of
the rocker with the dot on it puts the
switch in the
0 N position.
3-9
__
ON
REVISION LETT
UNDERSIDE
BOARD
S1-1
S1-8
Switch
Sl-l
SI-2
SI-3
Sl4
Sl-S
SI-6
Sl-7
SI-8
D
Figure
KK8-A (M8315) Central Processor Unit Switch Settings
Start
3-9
KK8-A
Function
in
memory field 7; (OFF position specifies Field 0)
(M8315)
Table 3-3
(When in
c
CPU
the
Module
"ON"
B
Position)
Start at address 4000
Start at address 2000
Start at address looO
Start at address 0400
Start at address 0200
CPU
Auto-Start Disabled
OFF
A
Starting
SI-2
the
address 0000
through
Auto-Start
Sl-6
feature
may
may
be
is
be
selected by leaving switches
ON
at
any
not
used.
time.
Failure
Sl-2
to
observe this
3-10
through
precaution
Sl-6
OFF.
Only
one
switch
will result in a malfunction, even
in
the
group
if
3.4.2 MS8-A
MS8-A, shown in Figure 3-10,
The
ry and
is
Read/Write
available in the following configurations:
Random Access Memory (RAM)
is a quad
module (M8311), semiconductor, read/write,
random
access memo-
Option
MS8-AA
MS8-AB
MS8-AD
If
through SI-6
OFF.
Memory Size
lK
2K
4K
you are using a
and
4K
SI-10
Module Number
M8311-YA
M8311-YB
M8311-YD
RAM
in Field 0, set switches SI-1
ON
and
turn
SI-7,
8,
and 9
CONNECTOR TO MRS-A
IF
13TH
BIT
ROM/RAM
MSS-A/MRS-A
CONFIGURATION
S1-1
THESE CHIPS
PRESENT ON
OR
MS311-YA
M8311-YB
NOT
Figure 3-10 MS8-A (M8311)
Read/Write
Random
S1-10
7015-8
Access Memory
3-11
Set switches
as
shown
in
Table
3-4
if
other
memory
configurations
are
used.
Table
34
MS8-A
Read/Write Memory Switch Settings
SI-1 ,2, and 3 Field Selection
SI-1 SI-2
81-3
Field Selected
ON
ON ON
0
OFF ON
ON
1
ON
OFF
ON
2
OFF OFF
ON
3
ON ON
OFF 4
OFF
ON
OFF
5
ON
OFF
OFF
6
OFF
OFF
OFF
7
Sl-4and5
First Address
SI-4 81-5 First Address
in
this
RAM
ON ON
0000
ON OFF
2000
OFF
ON
4000
OFF OFF
6000
SI-6
ON
for
4K
Memory M8311-YD, OFF for 1K or 2K
SI-7
OFF
SI-8
ON
for 2K Memory M8311-YB, OFF for
lK
or
4K
SI-9
ON
for
lK
Memory M8311-YA, OFF for 2K or
4K
Sl-10
Test switch, normally
ON
3.4.3 MRS-A Read-Only Random Access Memory
(ROM)
The
MRS-A,
shown in
Figure
3-11, is a
quad
module
(MS312), read-only,
random
access
memory
and
is avail-
able in
the
following configurations:
Option
MRS-AA
MRS-AB
MRS-AD
Memory Size
lK
2K
4K
3-12
Module Number
MS312-YA
MS312-YB
MS312-YD
Loading...