G E N E R A L E L E C T R I C
C O M P U T E R S
GE-200 Series Operating
Manual
G E - 2 0 0 S E R I E S
O P E R A T I N G M A N U A L
D e c e m b e r 1962 R e v . N o v e m b e r 1966
G E N E R A L E L E C T R I C
INFORMATION SYSTEMS DIVISION
PREFACE
This manual has been prepared a s a
guideto operating the central processor for the GE-225 Information Processing system. It includes a brief description of the major components of the system, general operating practices, system startup and shutdown, and a detailed description of the controls on the operator's cocsole and ty2ewriter.
P a r t I has been revised to include descriptions and illustrations of equipment not included in the e a r l i e r editions of this manual.
The appendix includes a section on number systems, a
table ofpowers of 2, and octal-decimal conversion tables. Much of the basic information about machine instruction repertoire and p r o g r a m s i s necessarily brief, since this information
iscontained in detail in the GE-225
Programming Reference Manual (CPB-252).
This manual supersedes the former GE-225 System Operating
Manual (CPB-247A).The operating information on peripheral subsystems contained in that manual is now covered in separate manuals for each subsystem.
Alist of these manuals appears
i n Appendix E.Much of the information in this manual is also applicable to the GE-205 and GE-215 central p r o c e s s o r s which
havevirtually identical
operatingcontrols and procedures.
In this revised edition, changes in technical content from the previous edition a r e identified
witha b a r in the margin opposite the change.
Suggestions and criticisms relative to form, content, o r use of this manual a r e invited. Comments may be sent on the Document Review Sheet in the back of this manual o r may be addressed directly to Document Standards and Publications, B-84, Computer Equipment Department, General Electric Company, 13430 North Black Canyon Highway, Phoenix, Arizona 85029.
@ 1962, 1964, 1966 by General Electric Company
(600 4 - 6 7 )
Page INTRODUC TION
A Typical Computer Center . . .
The GE-225 Information P r o c e s s i n g System . . . . . .
S y s t e m c o n f i g u r a t i o n
The C e n t r a l P r o c e s s o r . . . . . . . .. . . . . . . . . . . . . . . . .
Input-OutputDevices
. . .
C a r d R e a d e r s
. . .
C a r d p u n c h e s
ASA Seven-Track Magnetic Tape Controller . . .
M a g n e t i c T a p e S u b s y s t e m . . .
GE-225 OnIOff Line P r i n t e r . . . . . .
H i g h - S p e e d p r i n t e r
P a p e r Tape Reader and Punch . . . . . .
AuxiliaryComponents
Auxiliary Arithmetic Unit (AAU) . . .
M a s s Random Access Data Storage Unit . . .
DATANET-15* Data T r a n s m i s s i o n Controller . . .
Manual P e r i p h e r a l Switch Control Unit . . .
Document Handlers . . .
P r i o r i t y C o n t r o l . . .
O p e r a t o r ' s U s e o f Equipment . . .
GE -225 Instructions ...
OPERATOR'S DUTIES
Introduction . . .
Equipment and Operation Responsibility . . .
Actions Under Emergency Conditions . . .
F i r e . . .
Flood . . .
Power F a i l u r e . . .
Air Conditioning F a i l u r e . . .
Injury to P e r s o n n e l . . .
;. . .
Safety Considerations . . . . . .
General Site Operating P r o c e d u r e s
e . . .. .
ScheduleofComputerOperations . . .
Instructions to the Operator . . .
E r r o r and O p e r a t o r C o r r e c t i v e Action . . .
Computer Utilization Logs . . . . . .
L i b r a r y Storage and R e f e r e n c e
Files. . . . .
Assistance to the P r o g r a m m e r . . .
D e b ~ g g i n g e e ~ ~ ~ ~ e ~ ~ e e ~ ~ e e ~ ~ e ~ ~ ~ e ~ ~ e e e ~ ~ ~ ~ ~ ~ ~ ~ e ~ ~ ~ ~ e e ~ e e
Relationship Between Operator and Service Engineer
. . . e . eO p e r a t o r Behavior and Appearance . . .
*DATANET. Reg . T r a d e m a r k of the General E l e c t r i c Company
iii
F i g u r e Page I- 1 The GE -22 5 Information P r o c e s s i n g System
. . .
I- 2 The GE-225 System Using Punched C a r d Input and Output
. . .
I- 3 The 6 3 - 2 2 5 System Using P a p e r Tape Input and Output
. . . . . .
I-
4
The C e n t r a l P r o c e s s o r. . .
I - 5 The 400 Card-Per-Minute R e a d e r
. . .
I-
6
The High Speed C a r d ReaderI - 7 The 100 Card-Per-Minute C a r d Punch
. . . . . .
I- 8 The 300 Card-Per-Minute C a r d Punch
I-
9
ASA Seven-Track Magnetic Tape Controller. . . . . .
1-10 Magnetic Tape Subsystem
. . .
1-11 GE-225 On/Off Line P r i n t e r
1-12 High -Speed P r i n t e r
. . .
11- 5 11- 6 11- 7 11-
8
11-9
11-10. . .
P a p e r Tape Reader and Punch
. . .
The Auxiliary Arithmetic Unit
. . .
The Mass Random Access Data Storage Unit
. . .
DATANET-15* Data T r a n s m i s s i o n Controller
. . .
Manual P e r i p h e r a l Switch Control Unit
. . .
The GE 12-Pocket Document Handler (1200 Documents/Minute)
The 12 -Pocket Document Handler (750 Documents / Minute)
. . .
1-10Diagram of the GE-225 System
. . .
1-1 1Sample Schedule of Operations
. . .
11- 4Operator Instruction Sheet
. . .
11- 6Two Types of Operator Instruction C a r d s
. . .
11- 7Sample Reporting F o r m for Equipment Repair
. . .
11-9
Sample Daily Computer Log
. . .
11-10Sample Operator and Maintenance Log
. . .
11-1 1Sample T i m e C a r d
. . .
11-12Sample Tape Control F o r m
. . .
11-13Sample Log of Tape Use
. . .
11-14Sample Master P r o g r a m Change Request
. . .
11-15*
DATANET. Reg.
T r a d e m a r k of the General E l e c t r i c CompanyFigure Page 11-11
11-
12
IV- 1
IV-
2Iv-
3IV-
4v-
1Sample Hang-up Sheet . . . 11-17
Sample Debug Instruction Sheet . . . 11-18 . . .
The C e n t r a l P r o c e s s o r IV-
1. . .
The Maintenance Panel of the C e n t r a l P r o c e s s o r
N - 2. . .
The Control Console N -
4. . .
Control Switches on the Control Console IV-
6Console Typewriter . . . V -
1TABLES
Functions of Controls and Indicators on Central P r o c e s s o r . . . IV-
9. . .
Control Console E r r o r Conditions w-20
Typewriter E r r o r Conditions . . . v-
4glow green). T h i s p l a c e s the document handler's electronics in a standby condition.
4. D e p r e s s the MOTOR ON pushbut- ton on the control and indicator panel (will glow green).
5. D e p r e s s the ON-LINE, OFF-LINE MODE pushbutton on the control
and indicator panel f o r the d e s i r e d setting. (The ON-LINE o r OFF- LINE portions of the switch light alternately each time i t is depres- sed).
6. The document handler is not ready f o r u s e until the FEED READY light is illuminated; this o c c u r s a f t e r a delay of about a minute following the depression of the MOTOR ON pushbutton. (step 4).
f. Document handler (750 documents p e r minute) :
1. F o r on-line operation, turn on power to the c e n t r a l p r o c e s s o r . This t u r n s on power to the docu- ment handler adapter and the ' Z ' rack. (Steps 2 through 6 apply to both on-line and off-line oper- ation).
2. T u r n the c i r c u i t b r e a k e r switch on the document handler to the on position (up).
3. Check to s e e that the MAIN CIR- CUIT BREAKER indicator on the document handler's control and indicator panel is lit.
4. D e p r e s s the POWER ON pushbut- ton on the control and indicator panel (glows when lit).
5. Position the function switch on the control and indicator panel to PRO- CESS f o r on-line operation and to SEQUENCE f o r off-line operation.
6. The document handler is not ready f o r u s e until the FEED READY indicator is illuminated; this oc- c u r s a f t e r a delay of about a minute following the depression of the POWER ON pushbutton.
The o p e r a t o r will now be ready to s e t up the individual p e r i p h e r a l s f o r on-line operation. Directions f o r loading input and output media and setting up individual
p e r i p h e r a l s a r e contained in sections of this manual under headings of the specific peripherals.
S H U T D O W N PROCEDURES
The p r o c e d u r e s f o r turning power off and thereby shutting down the GE-225 System a r e the opposite of those f o r turning power on. S t a r t with the switches m o s t distant, electronically, f r o m the main power and work toward main power. That i s , turn off power to a peripheral, then to the controller, then to the c e n t r a l p r o c e s s o r , and l a s t of all, t u r n off the main power switches.
P e r i p h e r a l s may be turnedoff in any sequence desired.
The m o s t convenient o r d e r will depend on physical a r r a n g e m e n t of the equipment. If p a p e r tape and mag- netic tape a r e to be removed and s t o r e d , the o p e r a t o r
may wish to s t a r t with these units. The following sections describe p r o c e d u r e s f o r both n o r m a l shutdown and emergency shutdown.
Normal Shutdown
The following p r o c e d u r e s a r e to be followed any t i m e o p e r a t o r s go off duty and whenever s e r v i c e engineers p e r f o r m routine maintenance. T h e s e p r o c e d u r e s a r e designed to s a v e data in the c e n t r a l p r o c e s s o r c o r e m e m o r y and to prevent runaway p e r i p h e r a l s .
1. Magnetic tape s y s t e m :
a. Set the REMOTE/LOCAL switch to LOCAL.
b. Rewind and de-thread magnetic t a p e s (remove and s t o r e i f desired), relieve tension on tension a r m s , and close all dust c o v e r s and d o o r s on tape hand- l e r s .
c. D e p r e s s the POWER ON switchon each tape handler (light goes out).
d. D e p r e s s the POWER O F F switchon the tape controller.
2. P a p e r tape r e a d e r and punch:
a. Remove and s t o r e punched tape.
b. D e p r e s s the OPERABLE switch on control panel i f e i t h e r READER ON o r PUNCH ON indicators a r e on.
c. D e p r e s s the POWER ON switch (light goes off).
3. High speed p r i n t e r :
b. T u r n the circuit b r e a k e r switch to the off position (down).
a. D e p r e s s the O F F LINE switch on the controller.
b. D e p r e s s the POWER O F F switch on the controller.
4. C a r d punch:
a. Unload c a r d s f r o m input hopper.
b. D e p r e s s the MANUAL CYCLE switch until the punch is c l e a r of cards.
c. D e p r e s s the POWER O F F switch.
5. 400 C a r d p e r minute r e a d e r : Set the Power switch to the O F F position and the STOP/ENABLE switch to the STOP posi- tion.
6. Typewriter: P u t the power switch under right s i d e to O F F position (white will disappear in viewing window and O F F will appear).
7. 1000 c a r d p e r minute r e a d e r :
a. D e p r e s s the power O F F switch on the c a r d r e a d e r ' s control and indicator panel.
11. Document handler (750 documents p e r min- ute) :
a. D e p r e s s the POWER O F F pushbutton on the control and indicator panel.
b. T u r n the circuit b r e a k e r switch to the off position (down).
12. C e n t r a l p r o c e s s o r : After all p e r i p h e r a l s a r e turned off,
a. P u t the AUTO/M,~NUAL switch in the MANUAL position.
b. P u t the INSTR/WORD switch in the WORD position.
c. D e p r e s s the P W R O F F switch on the control panel.
13. Turn off a l l individual c l r c u i t b r e a k e r s at the main power panel. (The m a s t e r circuit b r e a k e r is normallv left on).
Before going off duty, the operator. would normally have a l l output media s t o r e d o r distributed to persons concerned and would remove 2nd file all input niater- ial.
8. M a s s random a c c e s s data s t o r a g e :
Emergency Shutdown a. D e p r e s s the POWER O F F pushbutton
on the electronia unit's control and indicator panel.
b. D e p r e s s the PWR O F F pushbutton on the controller's control and indicator panel.
9. Auxiliary arithmetic unit:
a. D e p r e s s the DC O F F pushbutton on the AAU maintenance panel.
10. Document handler (1200 documents p e r minute) :
a. D e p r e s s the MOTOR O F F pushbutton on the control and indicator panel.
In emergencies, equipment is shut down f b r protection of both the equipment and the personnel in the systenl room. In grave emergencies, such a s f i r e , flood, o r a malfunctioning power s y s t e m , the systenl is l e s s likely to suffer heavy damage i f the power is turned off a t the main power panel. In rninor e m e r g e n c i e s , such a s runaway tape units, jammed tape, o r shorts, in equipment, the o p e r a t o r will normally be required to turn off power only to the equipment and controller concerned. The gravity of the emergency will govern o p e r a t o r action. Whenever main power fails, main power switches should be turned off to prevent damage to the s y s t e m when power i s r e s t o r e d . Section I1 of this manual contains m o r e specific information on o p e r a t o r action under various conditions of emergency.
IV. CENTRAL PROCESSOR
GENERAL DESCRIPTION The console indicating and control panel (usually termed the control console) is mounted on the side of the f i r s t rack. Below the panel is the console desk The central p r o c e s s o r (Figure IV-1) p e r f o r m s the and above i t is the half -length door covering a main- computational (arithmetic), the storage, and the con- tenance control panel. Inside of the f i r s t rack a r e the t r o l functions f o r the GE-225 System. The p r o c e s s o r main power supply f o r the p r o c e s s o r , the power
is
housed in three equipment r a c k s which a r e bolted distribution panel, and the electronic control logic together. f o r the c a r d reader, c a r d punch, paper tape r e a d e r ,and paper tape punch.
Figure IV-1. The Central P r o c e s s o r
The second rack contains the majority of the elec- tronic counters, registers, timing circuits, and control logic associated with the processor.
The third rack contains the remaining registers, the magnetic core memory and i t s associated timing and control logic, and the logic for the controller selector.
Cable Connections
All peripherals a r e connected to the central proces- s o r by cables. The typewriter is connected directly by cable to the f i r s t rack of the central processor.
The card reader is also connected to the f i r s t rack, but through a junction box mounted in the r e a r of the
console desk.
The peripheral equipments which have controllers a r e connected to the controller selector by cables s o that each peripheral controller is connected in paral- lel with the controller selector and in s e r i e s with every other controller. Cables a r e connected to two plugs in the third rack of the central processor. The output cable from the central processor is connected to one plug, and leads to the input plug of the first controller. Controllers a r e connected to each other by cables which lead from the output of one to the
H A S R 5 )S68 DC
381 CHO 7 0 4 DS7
input of the next. The output of the last controller leads back to the controller selector, and connects to the second of the two plugs in the third rack of the central processor.
The card punch is connected to the central processor through a plug located on the same connector panel on the third rack a s the two plugs for the controller selector. The punch cable is clamped in place by means of a 'shoe' connector attached to the end of the cable.
Controls and Indicators
The GE-225 System operator constantly watches and uses the controls and indicators of the central proces-
sor. Most of the control switches and indicator
-
lights a r e on the control console which provides switches for manual control, indicates the status of equipment, and displays the contents of certain reg- isters. In ,addition to the control console, there is a maintenance panel which has three a r e a s of interest and use to the operator.
A. MAINTENANCE
PANEL.
The maintenance panel of the central processor, illustrated in Figure IV-2, is located inside the door which is above the control console. It is usedmostly by serviceCLE 1534 DC
Figure IV-2. The Maintenance Panel of the Central Processor
engineers, but t h e r e a r e two i t e m s of concern to the o p e r a t o r , the N r e g i s t e r indicators and the CLEAR N Switch.
N R e g i s t e r Indicators. These lights a r e located in the upper right c o r n e r of the maintenance panel and a r e labelled N1, N2, N3, N4, N5,
and N6. TL.ey show the contents of the N reg- i s t e r which is a BCD c h a r a c t e r representation of the input o r output f o r e i t h e r the p a p e r tape r e a d e r , p a p e r tape punch, o r the typewriter.
CLEAR N Switch. This switch is to the left and slightly below the N r e g i s t e r indicators.
When d e p r e s s e d , i t c l e a r s the contents of the N r e g i s t e r to zero. The o p e r a t o r u s e s t h i s switch
,
f o r example, when the typewriter is hung in a loop and depressing the space b a r does not c l e a r the N r e g i s t e r . T h i s could hap- pen i f someone t u r n s off the typewriter whilea p r o g r a m i s running. Depressing the CLEAR N switch and manually entering a TON instruc- tion will cause the typewriter to r e s u m e typing.
B. CONTROL CONSOLE. The control console (Figure IV-3) is the m o s t important and m o s t used panel on the GE-225. It is s o m e t i m e s r e f e r r e d to a s having both an indicator panel and a control panel, f o r the upper two thirds of the console contains indicator lights and the lower t h i r d contains control switches. The indicators a r e a l a r m lights, ready lights, and r e g i s t e r display lights f o r the A, I, and P r e g i s t e r s . The controls a r e option switches and control switches.
~ l a r m Indicators. The s i x a l a r m indicator lights in the upper left hand c o r n e r of the console a r e danger signals that indlcate e r r o r conditions have o c c u r r e d during system operation, and the p r o g r a m may be aborted. The cause can be an o p e r a t o r e r r o r , a programming e r r o r , o r a malfunction in the system equipment. A l l a l a r m indicators except the PRIORITY a l a r m can be turned off by the RESET ALARM switch.
However, i t must be r e m e m b e r e d that u s e of the RESET ALARM switch can damage the p r o g r a m i f used when not authorized to do s o by the p r o g r a m m e r . The conditions which cause these a l a r m s to come on a r e a s follows:
PRIORITY Alarm. This a l a r m is turned on under any of the following conditions:
1. The AUTO/MANUAL switch
is
in the MANUAL position.2. The STOP ON PARITY ALARM switch is engaged and a parity e r r o r is detected.
3. The c e n t r a l p r o c e s s o r does not have p r i o r i t y ( a c c e s s to memory).
4, A c a r d punch o r c a r d r e a d e r a l a r m condition has occurred.
PARITY Alarm. If the STOP ON PARITY ALARM switch is engaged when a p a r i t y e r r o r is detec- ted, the c e n t r a l p r o c e s s o r will halt. The PARITY a l a r m can b e turned off by p r e s s i n g the RESET ALARM switch o r by p r o g r a m m e d instructions.
The PARITY a l a r m i s turned on under any of the following conditions:
1. The memory-checking c i r c u i t s of the central p r o c e s s o r detect a p a r i t y e r r o r while the AUTO/MANUAL switch is in the AUTO position.
2. The parity checking c i r c u i t s associated with the p a p e r tape r e a d e r detect a parity e r r o r .
3. A p a r i t y e r r o r is detected as infor- mation is received f r d m a controller through the controller selector.
OVERFLOW Alarm. The c e n t r a l p r o c e s s o r does not halt on an overflow a l a r m . The a l a r m may be r e s e t automatically s e v e r a l t i m e s during a n o r m a l MPY instruction. The indicator a l s o can be turned off by depressing the RESET ALARM switch o r by p r o g r a m m e d instructions.
The OVERFLOW a l a r m is turned on under any of the following conditions :
1. The capacity of the A r e g i s t e r i s e x c e - eded during a r i t h m e t i c operations.
2. An illegal divide is attempted.
3. H one bit is shifted out of bit position one of the A r e g i s t e r during a shift- left operation.
CARD P U N C H Alarm. T h i s a l a r m is turned on any time a WCB, WCD, o r W C F instruction is attempted when the cardpunch is not in the ready condition. As already noted, the PRIORITY a l a r m a l s o c o m e s on, and the c e n t r a l p r o c e s s o r halts. The a l a r m can be r e s e t only by p r e s s i n g the RESET ALARM switch.
ECHO Alarm. This a l a r m is turnedonwhen the c e n t r a l p r o c e s s o r m a k e s an unsuccessful at-
tempt to select a controller through the con- t r o l l e r selector for an input/output operation.
The ECHO a l a r m light can be turned off only by depressing the RESET ALARM switch. The
a l a r m indicates the following conditions:
1. The selected controller is busy (delay not programmed).
2. An erroneous address was program- med, the addressedplug is not installed.
P 5 4 3 2 1 5 6 7 8 9 10 1 1 12 13 14 15 16 17 18 19
I 00 000 000 000 000 000 000
0 I 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 16 17 18 19
A 00 000 000 000 000 000 000
0 I 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 16 17 18 19
R E S E T A
iz-[pJ[-q[
A L A R M-
-
-
-
M A N U A L
E
DECIMAL M O D E
- -
-
Figure IV-3. The Control Console
- -
-
-
-
L
C A R D PUNCH R E A D Y
- -
E C H O A L A R M
-
B K O N L Y
-
-
-I ---- C A R D
R E A D E R READY
1
-
C A R D READER
E:k:
PUNCH C L R Q1
--
--
N REGISTER
READY
AIM
3. Controller is off line.
4. Power is off to controller.
5. Controller is malfunctioning.
CARD READER Alarm. This a l a r m is turned on when attempting to execute an RCB, RCD, o r R C F instruction while the c a r d r e a d e r is not in the ready condition. When the CARD READER a l a r m c o m e s on, the PRIORITY a l a r m a l s o c o m e s on and the c a r d r e a d e r and the c e n t r a l p r o c e s s o r halt. The a l a r m s in this com- bination a r e r e s e t only by depressing the RESET ALARM switch. The r e a d e r can be 'not ready' f o r any of the following r e a s o n s :
1. C a r d Reader is not turned on.
2. Input hopper is empty.
3. A c a r d is not positioned on the sensing platform.
4. Reader is busy (already reading a card).
5. A misfeed o r c a r d jam occurs.
Ready Indicators. The g r e e n ready indicator lights in the upper right c o r n e r of the control console give 'go-ahead' signals to the operator. With c e r t a i n exceptions, these lights come on when the c a r d punch and c a r d r e a d e r a r e ready f o r u s e o r when the N r e g i s t e r is ready to receive information. I f t h e equip- m e n t is not # ready f o r operation, an attempt to u s e i t will turn the ready light off and s e t an a l a r m indi- cator.
The s t a n d a r d ready indicators a r e the following:
CARD PUNCH READY. T h i s light is turned on to indicate that, in five r e s p e c t s , the cardpunch is ready to punch c a r d s . If the c a r d punch is not otherwise in an operable condition when a punch instruction is attempted, the ready light will go off and the CARD PUNCH andPRIORITY a l a r m s will come on. The five conditions of r e a d i n e s s which together turn on the CARD PUNCH READY light a r e :
1. The input hopper contains cards.
2. The s t a c k e r is not full.
3 . A c a r d is properly located a t station
'
one'.4. A c a r d is not currently being punched.
5 . The chip box is properly seated.
CARD READER READY. This light is turned on to indicate that, in t h r e e r e s p e c t s , the c a r d r e a d e r is ready to r e a d c a r d s . If the c a r d r e a d e r is not otherwise in an operable condition when a r e a d instruction is attempted, the ready light will go off and the CARD READER and PRIORITY a l a r m s will come on. The t h r e e conditions of r e a d i n e s s which t u r n the CARD READER READY light on a r e :
1. The input hopper contains enough c a r d s ( o r weight) to d e p r e s s the hopper- empty switch.
2. A c a r d is not c u r r e n t l y being read.
3. No misfeed o r c a r d jam is detected.
N REGISTER READY, This light c o m e s on to indicate that the N r e g i s t e r is ready to receive input o r output information. Specifically,
it
m e a n s that the r e g i s t e r is not currently being used by the typewriter, p a p e r tape r e a d e r , o r p a p e r tape punch. If an illegal code is placed in the N Register and a TYP command given, the N REGISTER READY light goes out and s t a y s out until a space key is struck.T h e r e are t h r e e m o r e indicators to the right of the ready indicators. These a r e :
AIM, The automatic i n t e r r u p t mode p'errnits
-
the simL!ltaneous ogeration of two o r m o r e p r o - g r a m s . When a p r o g r a m puts the conl2uter in the interrupt mode, the green AIM light conles onat
the time of the f i r s t i n t e r r u p t and re:n-ins02 until turned off under p r o g r a m zontrol o r i s turned off by the operator-. The operator can t u r n the AIM indicator off by p r o c e d l r e s de- s c r i b e d l a t e r in this section.
8K OTJLY. 011 a c o n l p ~ l t e r which h a s only an 8K m e m ~ y , this indicator i s on a l l the timc. A c o l n ~ l t e r wnich h a s a 16K menlory c a n b e s e t by the s e r v i c e engineer to operate either with the caxnplete (16K) memory o r with only half of i t (8K). The 8K ONLY indicator is l i t when the camputer is s e t to ogerate only with 8K; i t is off w!ien the corn2uter is s e t to operate with 16K.
DECLM-\I, M'03E. This indicator is l i t when the central pra:essor i s in the decimal mode.
When the i n j i c a t o r i s not lit, t h e p r o c e s s o r is in the binary mode.
1nrle.x Group Indicators. The five INDEX GROLTP display lights a r e located below the a l a r m I.ights and to the left of the P counter display lights. The lights a r e numbered one through five f r o m right to left. These five lights, r e a d a s binary digits, indicate
the index groap that has been selected by the p r o g r a m (Groups 0 through 3 1). Each group h a s four r e g i s t e r s , 0 through 3. When a l l lights a r e off, group z e r o is available without special selection. Only index groclp z e r o is s t a n d a r d on the GE-225 System; additional groups a r e optional. Any time a light is on in the index group, the o 2 e r a t o r knows that an index g r m p other than z e r o h a s been selected.
P Counter Lights. The fifteen display lights f o r the P counter a r e located to the right of the INDEX GROUP indicators. They a r e n ~ m b e r e d , l e f t to right, f r o m 5 through 19, and a r e a r r a n g e d in groups of t h r e e to facilitate reading the binary n u m l ~ e r s in their octal representation. By reading these groups, the oilerator can know the location of the instruction which a p p e a r s in the I r e g i s t e r . The P counter is useful wnen debugging a p r o g r a m and when checking f o r c o r r e c t operation after a manual branch comrnand to a p a r t i c u l a r p r o g r a m location.
SAVE: P Switch. This switch p e r m i t s the operator to r e t u r n to a p a r t i c u l a r position in t h e p r o g r a m a f t e r he h a s interrupted i t to make a correction, such a s to introduce an instruction manually. The SAVE P switch in the downpositionprevents the P counter f r o m incrementing. When the operator r e t u r n s the SAVE P switch to the up (normal) position a f t e r manual operations, the p r o g r a m is ready to continue f r o m the p l a z e of interruption. When the SAVE P switch is in the dowa position during the automatic mode of oper- ation, the instruction in the I r e g i s t e r i s executed o v e r and o v e r again.
I R e g i s t e r Lights. The 20 I r e g i s t e r display lights a r e lozated below the INDEX G R a 3 P and P counter lights, and a r e number f r o m 0 to 19. They display the contents of the instruction r e g i s t e r . Like the o t h e r r e g i s t e r display lights, they a r e r e a d in their o c t a l representation. The I r e g i s t e r displays the c u r r e n t instruction, the instruction that h a s not y e t been executed o r h a s been only partly executed.
A R e g i s t e r Lights. The 20 A r e g i s t e r display lights
a r e
located below the I r e g i s t e r lights. They a r e[-qp$[q
ALARMMANUAL
E
numbered f r o m 0 to 19, and display the contents of the A r e g i s t e r . These a r e a l s ~ r e a d in octal. By using the XAQ switch (described
later),
the A r e g - i s t e r lights can be u s e d to display the contents of the Q r e g i s t e r . All data and in;trclctions feed m2.nually into the central p r o c e s s o r go through the A r e g i s t e r , and a r e entered by u s e of the option switches.Optiojn Switches. The 20 option switches just below the A r e g i s t e r display lights a r e u s e d to feed infor- mation into the A r e g i s t e r . Each of these toggle switches e n t e r s information into the corresponding A r e g i s t e r position. The n u m b e r s 0 through 19 below the A r e g i s t e r lights may b e thought of as a l s o applying to the switches. When moved up, the switches a r e s p r i n g loaded and r e t u r n automatically to the center '(normal) position. When moved down, they r e m a i n in the down position until manually r e t u r n e d to the norm21 positio2.
W!len the central p r o c e s s o r is in the manual mode of operation, moving a n option switch up c a u s e s a one to be put into the corresponding position of the A r e g i s t e r . This is indicated by an A r e g i s t e r display light. Moving an option switch up h a s n9 effect when the central p r o c e s s o r i s in the automatic mode of operation.
Moving an option switch dow!~ w!len the central p r o c e s - s:lr is in the automatic mode c a u s e s a one to be put into the corresponding position of the A r e g i s t e r a t the time of a p r o g r a m m e d RCS instruction. Specified switches a r e left in the d a w ~ i p ~ s i t i o n while running c e r t a i n rodtines and while generating GAP a s s e m - blies. These and other special u s e s of the option switches a r e specified in the p r o g r a m ~ n e r ' s in s t r a c - tions to the operator.
RESE'i' ASwitch. This switch is to the left of the option switches. It i s effective only w!len the central p r o c e s s o r is in the m a w a l made of operation. Like the option switches, i t i s s p r i n g loaded in the up pgsition but not in the down position. When moved either up o r down, i t c l e a r s to z e r o the contents of the A r e g i s t e r , and t u r n s off a l l of the A r e g i s t e r display lights. When the operator m a k e s a mistake while using the option switches, he can c o r r e c t this
OFF
Figure IV-4. Control Switches on the Control Console
STOP ON
PARITY ALARM
m i s t a k e by clearing the A r e g i s t e r with the R.3SE'I: A switch and then s t a r t i n g over.
When the computer is in the a l t o m x t i c m3de, the o 2 e r a t o r m u s t be v e r y c a r e f u l nt2t to aczidentally lower the R-ZSET A switch. If he sh9uld lower i t accidentally, branzh cammands wvl~ld n ~ t oporate corre.2tly. The o p e r a t o r would proSably not kn3w of the e r r o r he caused until the p r o g r a m m e r r e p o r t e d back to him that the r u n was confused.
Toggle. When r e f e r r i n g to the toggle switches,
it
h a s become customary to u s e the t e r m toggle a s a verb. When u s e d in t h i s way,it
means to move the switch e i t h e r up o r down and immediately r e t u r n i t toits
original position.Control Switches
A s t r i p of switches along the bottom of the control console, and the SAVE P and RESET A switches just described, give the o p e r a t o r manual control over the c e n t r a l p r o c e s s o r and c e r t a i n functions of peripherals.
Eight of the switches a r e the pushbutton type that r e q u i r e only to be p r e s s e d momentarily to be activated.
T h r e e double-label switches a r e the r o c k e r type with two positions. F o r instance, the AuTO/MANUAL SWITCH is placed in the AUTO position by p r e s s i n g the end that is labeled AUTO and leaving that end in the d e p r e s s e d position.
These switches, illustrated in Figure IV-4, a r e des- c r i b e d a s follows:
PWR. ON, Depressing the PWR ON pushbutton t u r n s on DC power to the c e n t r a l p r o c e s s o r , the control console, and the 400 c a r d p e r min- ute r e a d e r . The pushbutton is a l s o an indicator, f o r i t lights when power is on.
PWR, OFF. When DC power i s on, depressing t h i s pushbutton t u r n s
it
off.RESET ALARM, This switch is effective only i n the manual mode of operation. Depressing the pushbutton c l e a r s any existing a l a r m con- dition. It t u r n s off the a l a r m lights and r e s e t s flip-flops s o the c e n t r a l p r o c e s s o r can continue operation. It does not c l e a r up the cause of the a l a r m .
LOAD CARD. This switch i s effective only in the manual mode of operation. Depressing the pushbutton initiates c a r d r e a d e r action and c a u s e s the r e a d e r to go through one load and r e a d cycle. It i s u s e d m o s t often to load the f i r s t c a r d into memory during p r o g r a m s t a r t u p operations, If no c a r d was on the sensing plat- f o r m . it moves one onto i t . F r o m t h e r e , the
c a r d is r e a d into mel-nory locations s t a r t i n g a t 0000.
RESET P. This switch is effective only in the manual mode of operation. Depressing the pushbutton c l e a r s the P counter to a l l z e r o s . It is u s e d most often to cause the first instruction to a d d r e s s memory cell zero, and is normally activated just before setting the AUTO/MANUAL switch to AUTO a t the beginning of p r o g r a m operation.
AUTO/MANUAL. This two-position, r o c k e r - type switch s e l e c t s e i t h e r the automatic o r the manual mode of operation f o r the c e n t r a l p r o - c e s s o r . When the AUTO portion of the switch is depressed, the c e n t r a l p r o c e s s o r is in the automatic mode, and instructions a r e p r o c e s s e d in a continuous sequence under p r o g r a m con- trol. When the MANUAL portion of the switch is depressed, the c e n t r a l p r o c e s s o r is in the manual mode, and the progranl is executed only one s t e p a t a time a s the START switch is depressed. Setting the AUTO/MANUAL switch to MANUAL during automatic operation c a u s e s the computer to halt operations a t the end of the instructiorl o r word being executed. The o p e r a t o r will r e c a l l that putting the c e n t r a l p r o c e s s o r in the manual mode c a u s e s the
PRIORITY a l a r m light to come on. The fol- lowing operations can be performed only when the AUTO/MANUAL switch is s e t to MANUAL:
1. C l e a r o r s e t information into a r e g - i s t e r with option switches.
2 . C l e a r a l a r m conditions with RESET ALARM switch.
3. R e s e t P counter with RESET P switch.
4. Load a c a r d manually using LOAD C a r d switch.
5. T r a n s f e r contents of A r e g i s t e r to I r e g i s t e r using A to I switch.
6. Txchange contents of A and Q r e g i s t e r s using XAQ switch.
INST/WORD, This is a l s o a two-position, r o c - ker-type switch which i s effective only in the manual mode of operation. It d e t e r m i n e s the length of the cycle of the c e n t r a l p r o c e s s o r during manual operations. When the INST por- tion of the switch i s depressed, the c e n t r a l p r o c e s s o r executes one conlplete instruction each time the START switch i s engaged. When the WORD portion of the switch is depressed, only one word t i m e i s executed each time the START switch i s engaged. The WORD position i s u s e d by the o p e r a t o r during s y s t e m s t a r t u p and shutdown.
START, In the automatic mode of operation, depressing the START pushbutton initiates act- ion. After the operation begins, the program r u n s automatically and despressing the START switch again has no effect. In the manual mode of operation, depressing the START switch causes the execution of one instruction o r one word time, depending upon the setting of the INST/WORD switch.
A 4 I (A to I). This switch i s effective only in the manual mode of operation. Depressing the A to I pushbutton t r a n s f e r s the contents of the A register, including the sign bit, to the I r e g i s t e r . The contents of the A r e g i s t e r r e - main unchanged, and can be cleared by tog- gling the RESET A switch. The A to I switch is used to manually load an instruction into the I r e g i s t e r o r to c o r r e c t an instruction already there.
XAQ. This switch is effective only in the man- r m o d e of operation. Depressing XAQ causes
an exchange of information between the A and Q r e g i s t e r s . That is, the contents of A go into Q and the contents of Q go into A. This permits the operator to observe the contents of the Q register. By using the RESET A switch and the option switches, the operator can clear and c o r r e c t the contents of the Q r e g i s t e r while saving the contents of the A register.
STOP ON PARITY ALARM/NORM, This is a two-position, rocker-type switch. It determines the response of the central p r o c e s s o r to the detection of
a
parity e r r o r . When the STOP ON PARITY ALARM portion of the switch is depressed, the central processor halts each time a parity e r r o r is detected and the PARITY and PRIORITY a l a r m lights come on. When the NORM (normal) portion of the switch is depres- sed, the central processor continues operation regardless of parity e r r o r s , and the only indi- cation of a parity e r r o r is the fact that the PARITY a l a r m light is turned on. The setting of the STOP ON PARITY ALARM/NORM switch is determined by the programmer. If he has included remedial action throughout the program to take c a r e of parity e r r o r s and to r e s e t the PARITY a l a r m light, he will specify the setting of the STOP ON PARITY ALARM/NORM switch to the NORM position. If he has not included remedial steps in the program, he will want the program to halt a t time of a parity e r r o r , s o will specify the setting of STOP ON PARITY ALARM,Table I contains a summary of the controls and indi- c a t o r s of the maintenance panel and control console.
It is recommended that the student operator remove the table from the manual and keep
it
in a handy place a t the console for quick reference.TABLE I.
FUNCTIONS OF CONTROLS AND INDICATORS O N CENTRAL PROCESSOR
r
Group
A l a r m Indicator Lights
Ready Indicator Lights
Control o r Indicator PRIORITY a l a r m light ( r e d )
PARITY a l a r m light ( r e d )
OVERFLOW a l a r m light ( r e d )
CARD PUNCH a l a r n l light ( r e d )
ECHO ALARM light ( r e d )
CARD READER a l a r m light ( r e d )
CARD PUNCH READY light (green)
Func t lon Indicates:
1. AUTO/MANUAL switch is in NlANUAL position.
2 , P a r i t y a l a r n l condition.
3 . C e n t r a l p r o c e s s o r does not have priority.
4. C a r d punch o r c a r d r e a d e r a l a r m condition.
Indicates:
1. Menlory -chec king c i r c u i t s of p r o c e s s o r detected p a r - ity e r r o r while p r o c e s s o r in autonlatic mode.
2 . P a r i t y e r r o r connected with tape r e a d e r .
3. Parl.ty e r r o r detected as data received f r o m a con- t r o l l e r through controller s e l e c t o r .
Indicates:
1. Capacity of the A r e g i s t e r was exceeded.
2. Illegal divide attempted.
3. Data shifted, l e f t o u t of the A r e g i s t e r .
Indicates c a r d punching was attempted when c a r d punch was not in a ready condition.
Indicates a n uilsuccessful atteixpt t o select a controller f o r ally of these reasons:
1. Controller busy 2 . I n c o r r e c t a d d r e s s 3. Controller off line 4. Power off to controller 5. Malfunctioning controller.
Indicates c a r d reading was
at-
ternpted while the c a r d r e a d e r was not ready (not s e t up, busy, misfeed, o r c a r d jam. )Indicates when c a r d punch is In ' r e a d y ' status.
Group
Ready Indicator Lights (Cont. )
Register Display Lights and Switches
Control o r Indicator CARD READER READY light (green)
N REGISTER READY light (green)
AIM light (green)
8K ONLY Indicator (green)
DECIMAL NODE Indicator (green)
INDEX GROUP indicator lights
P counter display lights
SAVE P switch
I r e g i s t e r display lights A r e g i s t e r display lights
Option Switches
RESET A switch
Function
Indicates when c a r d r e a d e r is in 'ready'status.
Indicates N r e g i s t e r is ready t o receive input/output information and no illegal o r improperly programmed instruction h a s
been given to typewriter o r paper- tape reader/punch.
Indicates that optional automatic interrupt mode is operative.
Indicates, when lit, that 8, 192 nleniory locations a r e available.
Indicates, when lit, that the c e n t r a l p r o c e s s o r is in the dec inlal mode.
Indicates index group that h a s been selected.
Display location of instruction in I r e g i s t e r ( s e e text f o r ex- c ept ion).
P r e v e n t s P counter f r o m incrementing.
Display c u r r e n t instruction.
Display contents of the A r e g i s t e r .
Feed infornlation into the A r e g i s t e r while in e i t h e r manual o r automatic modes and r u n special routines such as GAP a s s e m b l i e s in the automatic mode.
C l e a r s contents of A r e g i s t e r to all z e r o s when manual switch is engaged.
Group Control Switches
LOAD CARD switch C a u s e s c a r d r e a d e r to execute
RESET P switch R e s e t s P counter to all z e r o s
AUTO/NlANUAL switch Selects ailtoillatic o r nlanual inode of operation of c e n t r a l
INSTR/WORD switch Selects leng-tll of cycle of
START switch Initiates execution of one cycle
of operation (instruction o r word);
in autoillat ic
.
irlitllttes executionA '
I switch T r a n s f e r s contents of A r e g i s t e r to I r e g i s t e r (effective only when
Exchanges coiltents of A and Q
STOP ON PARITY ALARM/NORNl D e t e r m i n e s whether c e n t r a l Control o r Indicator
PWR ON switch
PWR O F F switch
RESET ALARM switch
Fuilc t ion
Applies DC power to the c e n t r a l p r o c e s s o r , and 400 card/minute r e a d e r .
T u r n s off DC power to the c e n - t r a l p r o c e s s o r , control console, and 400 card/minute r e a d e r . C l e a r s a l a r n l conditions (effec - tive only when MANUAL switch is engaged).
v
Function
Shows contents of N r e g i s t e r input o r output for the paper tape r e a d e r , paper tape punch, o r typewriter.
C l e a r s contents of N r e g i s t e r to zero.
Group Mainteilanc e Panel
Control o r Indicator N register indicators
CLEAR N switch
SETUP PROCEDURES
Setting up the c e n t r a l p r o c e s s o r f o r operation involves only bringing power up and setting control switches.
The s i x s t e p s listed below a r e designed to s a v e data in the c o r e m e m o r y of the c e n t r a l p r o c e s s o r . If the console was previously shut down by the normal p r o - cedure and switches have not been disturbed, s t e p s 2 and 3 r e q u i r e only verification. Some o p e r a t o r s f o r m the habit of checking switches both visually and physically by actually p r e s s i n g a switch even though i t a p p e a r s to be in position already. Thus, good habit p a t t e r n s a r e formed. (EXCEPTION: Don't hit PWR ON when a l r e a d y on, except when performing special p r o c e d u r e s as described later.)
1. Verify that blowers in c e n t r a l p r o c e s s o r cabinets a r e operating. (If not, call the s e r v i c e engineer.)
2. Set the AUTO/MANUAL switch to the MANUAL position.
3. Set the INSTR/WORD switch to the INSTR position.
4. D e p r e s s the PWR ON switch.
5. S e t the INSTR/WORD switch to the INSTR position.
6. D e p r e s s the RESET ALARM switch (this can be done e i t h e r a t this time o r just
, p r i c r to s t a r t i n g a program.)
The complete p r o c e d u r e f o r starting up and shutting down the central p r o c e s s o r and the entire GE-225 System is described in Section 111.
M A N U A L OPERATING PROCEDURES The option switches on the control console p e r m i t the o p e r a t o r to e n t e r instructions and data manually;
the r e g i s t e r display lights p e r m i t the reading of the contents of m e m o r y and of c e r t a i n r e g i s t e r s . Thus, i t is possible to feed in and execute a s h o r t p r o g r a m and r e a d the results. Manual loading is used most, however, f o r getting a p r o g r a m s t a r t e d , correcting m e m o r y , brz nching, setting and clearing special modes, and reproducing damaged c a r d s . Once an o p e r a t o r completes the n e c e s s a r y manual operations and gets a p r o g r a m s t a r t e d , control of operations is usually t r a n s f e r r e d to the c e n t r a l p r o c e s s o r .
Loading an Instruction Manually
Any instructiori that is intelligible to the GE -225 can be loaded manually by putting the octal equiva-- lent of the instruction into the A r e g i s t e r , a s follows:
1. Set the AUTO/"MANUAL switch to the MAKUAL position.
2. Set the INSTR/WORD switch to the INSTR position.
3. Toggle the RESET A switch to c l e a r the k r e g i s t e r .
4. Load the octal equivalent of the instruction into the A r e g i s t e r . (See instructions f o r toggling option switches in the previous section.)
5. D e p r e s s the A to I switch.
6. Toggle the RESET A switch and load any n e c e s s a r y data into the A r e g i s t e r . (Not n e c e s s a r y f o r s o m e instructions.)
7. D e p r e s s the START switch.
The central p r o c e s s o r w i l l then execute the instruc- tion placed in the I - r e g i s t e r by the operator.
The following a r e the m o s t used instructions, and m u s t be nlemorized a s quickly a s possible.
Mnemonic Description Octal Code
TON RON
WCD WCB WCF RCD RCB RC F BRU
S E T DECMODE SET BINMODE SXG Y
ST A LDA O F F
Typewriter 011
Paper. 'l'ape Reader On
Paper. Tape Purich On
W r i l e C a r d Do(li111a1 Write C a r 6 Binary Write Card Full Read C a r d s Bec,inlal Read C a r d s Binary Read C a r d s Full Branch Uncondi- tionally
S e t Decimal Mode Set Binary &lode Select Index Group S t o r e A
Load A
Input, Output Off Loading Data Manually
When data is to be loaded into m e m o r y , the fol- lowing procedure is followed:
1. Set the AUT0;MARUAL. switch to the MAN UAL position.
2. Set the IKSTR/WORD s w i t c h to the INSTR position.
3. Toggle the RESET A switch.
4. Load an STA instruction in the A r e g i s t e r (Store A is an octal 0300000), with the m e m o r y a d d r e s s where the data i s to b e s t o r e d replacing the 13 righthand bits of the STA instruction.
5. D e p r e s s the A to I switch.
6. Toggle the RESET A switch.
7. Load the octal equivalent of the data to be s t o r e d into the A r e g i s t e r .
8. D e p r e s s the START switch.
Load additional words by repeating s t e p s 3 through 8.
Manual Branching
P r i o r to executing a p r o g r a m , the o p e r a t o r may p e r - f o r m such manual operations as checking m e m o r y , feeding constants into the memory, o r correcting memory. To then t r a n s f e r to automatic operation, the o p e r a t o r m u s t manually e n t e r a branch i n s t r u c - tion which contains the location of the f i r s t instruction to be executed. T h i s is done as follows: (Power is on and the INSTR/WORD switch is in the INSTR posi- tion.)
1. S e t the AUTO/MANUAL switch to theMAN- UAL position.
2. Toggle the RESET A switch.
3. Load a BRU instruction into the A r e g i s t e r (octal 26 in positions 0 through 4 and the m e m o r y location of first instruction to be
executed in positions 7 through 19).
4. D e p r e s s the A to I switch.
5. S e t the AUTO/MANUAL switch to the AUTO position.
6. D e p r e s s the START switch,
If the o p e r a t o r wishes to branch and r e m a i n in manual mode, he m a y u s e the above procedure omitting Step 5 (that is, leave AUTO/MANUAL switch in MANUAL mode). If the o p e r a t o r branches to the f i r s t instruction of a s t o r e d p r o g r a m , one instruction is executed each t i m e the START switch is p r e s s e d .
Entering and Leaving Upper Memory
In o r d e r to get into upper m e m o r y (memory loca- tions 8192 and above), i t is n e c e s s a r y to u s e a basic
branch instruction modified by index r e g i s t e r 1, 2, o r 3. The index r e g i s t e r m u s t contain a constant of 8192 (decimal). The octal equivalent of 8192 is 0020000, which m e a n s that bit position s i x is turned on and all o t h e r s a r e turned off. Thus, any t i m e bit position s i x is on in the P counter indicator lights, the o p e r a t o r will know the c e n t r a l p r o c e s s o r is in upper memory.
The following s t e p s t r a n s f e r operations to upper memory:
1. S e t the AUTO/MANUAL switch to the MAN- UAL position. (It is a s s u m e d that the INSTR switch is engaged).
2. S e t a Store A instruction into the A regis- t e r . (STA is an octal 030000X, where X is 1, 2, o r 3 f o r the index r e g i s t e r ) . 3. D e p r e s s the A to I switch.
4. Toggle the RESET k switch.
5. S e t an octal 0020000 into the A r e g i s t e r . 6. D e p r e s s the START switch. (Stores con-
stant into index r e g i s t e r selected).
7. Toggle the RESET A switch.
8. Set into the A r e g i s t e r a BRU to the de- s i r e d m e m o r y location modified by the selected index r e g i s t e r used in s t e p 2, above.
9. D e p r e s s the START switch.
To t r a n s f e r f r o m upper memory to lower mem- ory, follow the above s t e p s , except step 5.
The effect then is that s t e p 6 (START) s t o r e s z e r o s into the index r e g i s t e r being used.
Reproducing Individual Cards
In an emergency, i t m a y be n e c e s s a r y to reproduce
a
single card. The following d e s c r i b e sa
quick method of doing this with manual instructions. I t is a s s u m e d that the c a r d punch is ready f o r operation and thatits
input hopper is loaded with blank c a r d s .1. Feed the c a r d to b e reproduced into the feed r o l l e r s of the c a r d r e a d e r to position
it
on the sensing platform.2. Set the AUTO/MANUAL switch to the MAN- UAL position.
3. By using option switches, s e t
a
read-card instruction into the A r e g i s t e r :a. If a binary c a r d , u s e RCB, octal 250YY01.
b. If a decimal c a r d , u s e RCD, octal 250YYOO.
YY is the s t a r t i n g a d d r e s s where the c a r d is to b e read. The handiest a d d r e s s is z e r o ; i f this cannot be used, r e m e m b e r that the a d d r e s s m u s t be a multiple of 1 2 8 and l e s s than 2048; that is, multiples of octal 200 and l e s s than octal 4000.
4. D e p r e s s the A to I switch.
5. Hold down the hopper-empty switch on the c a r d r e a d e r and p r e s s the START switch on the console. ( r e a d s c a r d s )
6. By using option switches, s e t a write-card instruction into the A r e g i s t e r :
a. If a binary c a r d , u s e WCB, octal 250YY03.
b. If a decimal c a r d , use WCD, octal 250YY02.
7. D e p r e s s the A to I switch.
8. D e p r e s s the START switch. (punches c a r d s ) 9. D e p r e s s the MANUAL CYCLE switch on the c a r d punch twice to c l e a r punched c a r d into output hopper.
If m o r e than one copy of the c a r d is needed, repeat s t e p s 7 and 8 a s many t i m e s as t h e r e a r e c a r d s needed (the w r i t e - c a r d instruction r e m a i n s in A and can b e t r a n s f e r r e d to the I r e g i s t e r and executed as many t i m e s as necessary.)
Saving Information in A
When an o p e r a t o r manually e n t e r s changes to a pro- g r a m , i t is usually n e c e s s a r y to s a v e information in the A r e g i s t e r before entering new information. It m u s t be r e m e m b e r e d , however, that changes should n e v e r be made by this method without instructions to do s o by the p r o g r a m m e r . The procedure f o r saving the information in the A r e g i s t e r and the location of the P counter is as follows:
1. P l a c e in a down position the option switches corresponding to the ones (the lights) of the A r e g i s t e r . These switches a r e now a r e m i n d e r to the o p e r a t o r of what was originally in A.
2. R a i s e the RESET A switch to c l e a r the A r e g i s t e r .
3. Lower the SAVE P switch to s a v e the infor- mation in the P counter.
4. Raise the optioil switches corresponding to the ones of the new information to be e n t e r e d into A. Return to the down position any of the switches which w e r e in that position ( a s a r e s u l t of s t e p 1).
5. Move the new information now in the A r e g i s t e r to w h e r e v e r i t will be u s e d in the p r o g r a m , f o r example, move
it
to the I r e g i s t e r by d e p r e s s i n g A to I (See "Load- ing Data Manually))).6. Raise the RESET A switch to c l e a r the A r e g i s t e r .
Raise to the up position all of the option switches which a r e down ( a s a r e s u l t of step 1). Since the switches a r e s p r i n g loaded, they will autonlatically r e t u r n to the normal position. This r e t u r n s the o r i - ginal information to the A r e g i s t e r by entering ones into A to correspond with the down switches.
8. Raise the SAVE P switch (lowered in step 3 ) to r e s t o r e the original iirfornnation to the P counter.
Extracting Data from Memory
~ f t e r a s e r i e s of i r ~ s t r u c t i o n s o r data h a s been loaded, the o p e r a t o r may want to check the contents of mem- ory. The following s t e p s can be used any time the o p e r a t o r wishes to know what is in any p a r t i c u l a r cell in memory. Once the information is displayed, i t is a simple m a t t e r to c o r r e c t i t and return i t to m e m o r y ( s e e 'Loading Data Manually'). It is a s s u m e d the AUTO/MANUAL switch is s e t to MANUAL and the INSTR~WORD switch is s e t to INSTR, and no a l a r m s lights a r e on.
1. If i t is d e s i r e d to s a v e P, s e t the SAVE P switch.
2. Toggle the RESET A switch, thus leaving an LDA instruction in the A r e g i s t e r (Load A i s an octal 00).
3. Load the memory location of the informa- tion d e s i r e d into bit positions 7 through 19 of the A r e g i s t e r .
4.
D e p r e s s the A to I switch.5. D e p r e s s the START switch.
The contents of the m e m o r y location specified in step 2 now a p p e a r s in the A r e g i s t e r .
