IBM 1401 Data Processing System Reference Manual

Reference Manual

1401 Data Processing System

Original Equipment Manufacturers' Information

The information in this manual will assist designers of accessory equipment for

IBM

1401 Processing Units. Additional details about operation and use of the

IBM

1401 Processing

Unit in integrated data processing systems may be obtained from the local

IBM sales office.

1)

1961 by International Business YIachines Corporation

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Reference Manual

1401 Data Processing System

Original Equipment Manufacturers' Information

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Figure

1.

IBM

1401 Processing Unit

Contents

Introduction ................................................... 5

Functional Characteristics· . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5

Core Storage .................................................... 5

Instruction Format ............................................... 5

A- and B-Registers ......... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6

Address Registers ................................................ 6

Word Mark....................................

Checking ......................................

Input/Output Attachment .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

......... 7

. . .. . .. .. 7

7

Physical Characteristics ........................................

7

Console. . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7

Auxiliary Console .................................. .. . . . . . . . . .. 10

Customer Engineering Diagnostic Panel ............................ 11

Power Requirements ............................... . .......... 13

Signal Levels· ................................... .

13

Input/Output Signal Lines .....................

IBM

1401 Output Lines to I/O Unit . . . . . . . . . . . . . . . .

14

14

I/O Unit-Input Lines to

IBM

1401 ................................ i'

17

Connector Receptacle Pin Assignments ............................. 18

IBM 1401 Processing Unit

This manual is intended to provide sufficient data to satisfy the special needs of non-IBM engineers who wish to att~h the processing unit of the IBM 1401

Data Processing System to their equipment. It provides easy access to supplemental tie-in data not as readily available in other IBM publications.

Detailed theory of operation and mechanical principles of operation are not included. These can be found in the IBM customer engineering manual of instruction for the 1401 system. Additional engineering information can be had from systems logic diagrams and other engineering documents available.

Additional details relating to operation and use of the 1401 can be found in IBM reference manuals describing data processing systyms and in customer engineering manuals for units attached to the 1401, or systems using the 1401.

Functional Characteristics

The IBM 1401 Processing Unit (Figure 1) is a completely transistorized, high-speed, advanced data processing machine.

No control panels are used in the 1401. Operation is controlled entirely by stored programming. A program routine is stored in the core storage unit before processing begins. Processing then proceeds, step by step, through the stored program routine, analyzing each instruction and performing the function called for before going to the next instruction.

Core Storage

Storage capacity is 1,400, 2,000, 4,000, 8,000, 12,000, or

16,000 alphamerical characters of 8-bit core storage.

The eight bits consist of six bits for the alphamerical binary code, one bit for the word mark used to define word length, and one bit for the odd-redundancy parity check.

Core storage operates serially on an l1.5-microsecond storage cycle. This normally consists of 3 microseconds for storage read out, 3.5 microseconds for data manipulation, and

.5 microseconds for data regeneration.

All storage positions are addressable. Each position is identified by a 3-character address. The first 1,000 positions of storage have the addresses 000-999. The next 3,000 positions use an alphabetic or special character in the hundreds position of the address.

The 12,000 additional core-storage locations are addressed by the presence of zone bits located over the units position of each storage address over 3,999. These zone bits are added to the basic 4,000-character coding system.

The IBM 1401 addresses core storage locations by assigning a digit value to each bit that appears over the hundreds and units position of the 3-character address.

Instruction Format

Variable word-length instructions are used in the 1401.

Instruction length can vary from one to eight characters.

Op (A/I) (B) d

X XXX XXX X

Op is a I-character operation code that defines the basic instruction. The Op-code position must also con-

Functional Characteristics 5

I

ACTUAL ADDRESSES

0000 to 0999

1000 to 1999

2000 to 2999

3000 to 3999

4000 to 4999

5000 to 5999

6000 to 6999

7000 to 7999

8000 to 8999

9000 to 9999

10000 to 10999

11 000 to 11999

ZONE BITS OVER

HUNDREDS POSITION

No Zone Bits

A-Bit (Zero-Zone)

B-Bit (ll-Zone)

AB-Bits (12-Zone)

No Zone Bits

A-Bit (Zero-Zone)

B-Bit (ll-Zone)

AB-Bits (12-Zone)

No Zone Bits

A-Bit (Zero-Zone)

B-Bit (ll-Zone)

AB-Bits (12-Zone)

ZONE BITS OVER

UNITS POSITION

No Zone Bits

No Zone Bits

No Zone Bits

No Zone Bits

A-Bit (Zero-Zone)

A-Bit (Zero-Zone)

A-Bit (Zero-Zone)

A-Bit (Zero-Zone)

B-Bit (ll-Zone)

B-Bit (ll-Zone)

B-Bit (ll-Zone)

B-Bit (ll-Zone)

3-CHARACTER

ADDRESSES

000 to 999

+00 to Z99

000 to R99

~OO to 199

00+ to 99Z

+0+ to Z9Z

00+ to R9Z

+

00+ to 19Z

000 to 99R

+00 to Z9R

000 to R9R

+-

000 to 19R

12000 to 12999

13000 to 13999

14000 to 14999

15000 to 15999

No Zone Bits

A-Bit (Zero-Zone)

B-Bit (ll-ZoMl)

AB-Bits (l2-Zone)

AB-Bits (12-Zone)

AB-Bits (l2-Zone)

AB-Bits (12-Zone)

AB-Bits (12-Zone)

Figure 2.

IBM

1401 Addressing System tain a word mark. (This word mark is set under program control.)

(A/I) is a 3-character storage address. A is the address of a data word in the A -field. I is the address of the next instruction to be executed if a branch occurs.

( B) is a 3-character storage address of a data word in the B-field. The d is a I-character modifier to the operation code.

The variable-length instructions can take six different forms. Figure 3 shows examples of these six possible combinations.

000 to 991

+o~ to Z91

Dot

to R91

006 to 191 instruction character to be used by the stored program.

2. A-address register contains the storage location of the data in the (A) portion of an instruction.

3. B-address register contains the storage location of the data in the (B) portion of an instruction.

NUMBER OF

POSITIONS

OPERATION

INSTRUCTION

FORMAT

Read

Op

1

A-

and

B-Registers

These registers are single-character storage devices used for storing the specific characters being treated.

The single-character storage output enters the B-register in parallel from the cores. The A-register can. receive one character at a time from the B-register.

Characters thus stored may be added, subtracted, compared, or otherwise treated. Information can be written back into storage from either register.

2

5

7

Stacker Select

Branch

U ncond itiona I

Branch Unequal

Add

Op d

K 2

Op (I)

B 400

Op (I) d

.! 625

/

Op (A) (B)

A 072 423

Address

Registers

There are three 3-digit address registers:

1. I-address register contains the location of the next

8

Test Character and Branch

Figure 3. Instruction Formats

Op

(I) (B) d

!. 650 080 4

6

Word

Mark

The use of variable-length instruction and data fonnat requires some means for determining the instruction and data word length. A word mark serves this purpose. The word mark indicates data word size.

It also indicates read in completion of the preceding instruction, causing the beginning of an execution cycle.

Rules governing word mark use are:

1. Word marks are not moved with data, except when a

LOAD instruction is used.

2. When moving data from one location to another, only one field requires a defining word mark, because a

MOVE instruction implies that both fields are the same length. If the fields are of different lengths, the first word mark encountered defines the length of both fields and stops the operation.

B. For an arithmetic operation, the B-field must have a defining word mark. The A-field must have a word mark only when it is shorter than the B-field.

4. A

LOAD instruction moves the A-field word mark to the B-field, and clears any other word marks in the

B-field up to the length of the A-field.

5. A word mark must be located in the high-order character (operation code) of each instruction.

6. Two operation codes are provided to permit setting and clearing word marks.

Checking

All data processed in the 1401 is parity checked at various locations; that is, checked to see that an odd number of bits exist in a character. Parity checks are made of the A- and B-registers, the inhibit lines (storage check), the Op-register and the storage-address register.

Characters are also validity checked when read into storage; that is, checked to insure that o~ly valid characters are entered into storage. This checks the bit configuration representing each character in storage.

Additionally, a hole-count check is available when card equipment is used with the 1401. This counts the number of holes in each column of each card, to establish that it is equal to the number of holes called for in the same card at the previous read or punch station.

Input /

Output Attachment

The input/output attachment circuitry and cable connection to the 1401 allows an input/output unit to be attached to the 1401 without requiring further modifications to the 1401 circuitry.

The I/O unit must be attached to the 1401 so that an exchange of signals between the two is possible.

The data lines accept one character at a time, utilizing a 7 -bit BCD code plus a word-mark bit if required. The character rate can be any value up to a maximum of 86 kc. The exact character rate depends on the characteristics of the device attached to the

1401. The input/output unit controls the 1401 clock after the I/O unit has been instructed to read or write.

The 1401 is locked up between characters.

It

is required that each I/O unit have at least a onecharacter register (or equivalent) to which a character can be sent or from which a character can be received.

Physical Characteristics

Console

Keys and Switches

Console keys and switches are shown in Figure 4.

POWER ON

Pressing this key turns power on in the system and causes the power on key to light. It also causes all control triggers and latches to be reset, and turns on the

DELTA I cycle latch.

POWER OFF

Pressing this key turns power off in the system.

START RESET

This switch resets all control triggers and latches in the system, and turns on the

DELTA I cycle latch.

I/O CHECK STOP

When in the

ON position (up), the 1401 stops at the completion of an I/O operation if an error occurs during that operation. When in the

OFF position, the

1401 will not stop automatically after an 1/

0 error detection, With the switch in the

OFF position, error detection must be accomplished by programming.

START

This key is used to initiate or resume machine opera-

tion fo!lo\xling a manual, programmed, or automatic

stop. Keys serving the same function are normally

Physical Characteristics 7

Figure 4.

IBM

1401 Console found on the I/O units within the system. Operation of this key is conditioned by several modes:

1. During a normal

RUN mode, the system can be started by pressing the start key on any of the units.

2. During a

SIKGLE CYCLE PROCESS mode, any of the start keys can cause the system to advance through an instruction (except for I/O instructions) one cycle at a time. For I/O instructions, the system advances through the instruction portion one cycle at a time, but goes through the execute portion at high speed.

3. To restart following an error indication, the check reset key must be pressed before operation of the start key.

4. Following a card jam or misfeed in the card I/O equipment, the cards in the associated feed must be run out by means of the non-process run out key for that feed, and the hopper must be reloaded before pressing the start key.

STOP

This is a lighted key, and is used to stop processing in the system manually. vVhen in the

RUr\" mode, however, it does not take effect until the instruction being executed has been completed.

EMERGENCY OFF

This is a pull switch. Pulling this switch disconnects all power to the entire system. The switch must be manually reset by a qualified technician before power can again be applied to the system.

8

CHECK RESET

An error detection by the checking circuits causes this key to light. It must be pressed following a 1401 error, before the start key can be effective.

I-ADDRESS REGISTER vVhen this key is lit, it indicates that the I -address register was the last address register to address storage and that the storage address display is displaying the

I -address register contents. When the light is off, pressing this key causes it to glow and causes the contents to be displayed by the storage address display.

A - ADDRESS REGISTER

This key operates the same as the I -address register key, but for the A-address register.

B-ADDRESS REGISTER

This operates the same as the I-address register key, but for the B-address register.

MANUAL ADDRESS

These four switches are used to select the address to be entered in the storage address register. From left to right, the switch positions are: thousands, hundreds, tens, units.

These switches are also used to select a storage location for a display or alteration, without disturbing the contents of the address registers.

SENSE SWITCHES

Seven sense switches can be included in the

IBM

1401.

Switch A is standard in most systems; the other six

(B, C, D, E, F, and G) are optional. Switch A is used to control last card operations by making the

TEST AND

BRANCH instruction effective only when the last card in the reader has passed the seca'nd read brushes.

MODE SWITCH

The nine-position mode switch selects the nine modes of operation.

Run:

This is the normal mode of operation in which the machine is under control of the stored program.

I/EX (Instruction /Execution):When

the mode switch is in this position, the first time the start key is pressed, the machine reads one complete instruction from storage and stops. This is the I (instruction) phase. The next pressing of the start key allows the machine to perform the execution of t.hat instru.ction.

Single Cycle Process:

When set for this mode of operation, each pressing of the start key causes the machine to take one 11.5-microsecond storage cycle,

and to ad,'ance through the instruction and execu-

tion portions of the program one character at a time.

Single Cycle Non-Process:

This mode of operation is similar to the

SINGLE CYCLE PROCESS mode, except that no data is allmved to enter storage from the

A-register or the logic unit. This mode permits observing the results of arithmetic operations, one character at a time, in the logic display without destroying the original B-field data.

Character Display:

vVhen operating in this mode, pressing the start key causes a character at an address in storage (selected by the manual address switches) to be displayed in the B-register.

Storage Print-Out:

This mode of operation permits any

100-character block of storage to be printed. The hundreds and thousands manual address switches are used to select the desired block of storage.

Alter:

This mode of operation permits the operator manually to change the contents of any address register or storage location.

Storage Scan:

When in this mode, pressing the start key causes the 1401 to start reading out of storage beginning at the address set in the manual address switches.

If any error condition is detected that had been previously set by the 1401 process unit or by an input/output device, the machine stops, and the check lights in the process unit and the corresponding input/output unit turn on. The storage address display unit shows the location of the error.

The B-register contains the storage position in which the error was detected. Using the bit switches and enter key corrects the actual location in storage.

After the error condition is corrected, the mode switch is again set to

STORAGE SCAN.

Pressing the start key again causes a read-out of storage beginning at the address set in the manual address switches, and continuing to the end of storage if no other errors exist.

Address Stop:

In this mode, pressing the start key starts the program and the machine stops at the address selected by the manual address switches.

TAPE SELECT S'llITCH

This rotary switch is set to the normal position (N) during automatic operation. The switch can be set to the numbers (1-6) that correspond to any of the attached tape units, when manual operation is desired.

D-position is a diagnostic position of the switch. The

D-position controls tapes from memory the same as the N-position. D-position permits an

~rror to be retained in A and B

skew register

on the customer engi-

neering diagnostic panel \:vhen the error stop s\xlitch

is

ON.

Physical Characteristics 9

BACKSP ACE KEY

This key works in conjunction with the tape select switch. When the switch is set to a specific tape unit, pressing this key causes the tape in the selected unit to backspace over one group of records until an interrecord gap is sensed.

TAPE LOAD KEY

When this key is pressed, tape unit 1 is automatically selected and tape data starts loading at address 001 and continues until an inter-record gap is sensed.

STORAGE ADDRESS

This light glows red when an address register parity check or validity check occurs. The lights underneath indicate the four coded characters and the check-bit status of the characters in the storage-address register.

INSTRUCTION LENGTH

These lights indicate the number of characters in the instruction.

Auxiliary Console

Lights

Console lights are shown in Figure 4.

PROCESS, READER, PUNCH, PRINTER, AND TAPE

When the machine stops because of an error, one of these lights will glow red to indicate the source of the error.

STORAGE

This light glows red when a parity check detects an error at the input to storage.

B-LIGHT

This light glows red when a B-register parity check occurs. The lights underneath display the coded character, check-bit status, and the word mark status of the character in the B-register.

A-LIGHT

This light glows red when an A-register parity check occurs. The lights underneath display the coded character, check-bit status and the word mark status of the character in the A-register.

LOGIC LIGHTS

O-Flo:

This light glows when an overflow condition exists.

BFA:

This light glows when an unequal-compare condition exists after a

COMPARE instruction. Additional lights are provided for high-low-equal compare when this feature is included in the system.

BIT DISPLAY

Displays the bit configuration of the characters being pr,ocessed in the arithmetic section.

OP-REGISTER

The Op light glows red when an incorrect operation code exists in the Op-register, or if the code is incorrectly decoded. The lights underneath indicate the coded character and check-bit status of the character in the Op-register.

Keys, Switches and Lights

Figure 5 shows auxiliary console keys, switches, and lights.

BIT SWITCHES

Eight bit switches are available for use in altering a character in storage. These switches set the bit structure of the required character when the mode switch is in the

ALTER position (see Mode Switch: Alter).

ENTER

Pressing this key, with the mode switch set to

ALTER, enters the character determined by the bit swtiches into a position in storage.

I/O CHECK

RESET

Pressing this switch, with the I/O check stop switch in the

OFF position, resets the I/O error latches.

PROCESS CHECK STOP

This switch is normally on, causing the machine to stop automatically when a process check occurs. When in the

OFF position, the machine does not stop on process checks, except for Op-register and addressregister checks.

READ L~TERLOCK

With this light off, the reader is interlocked until the print operation is complete. When on, the reader is in a ready condition.

PUNCH INTERLOCK

When this light is off, the punch is interlocked until completion of the print operation. When this light is on, the punch is in a ready condition.

PRINTER DISPLAY

This light is on when a print operation is being executed.

RUN

When this light is on, the printer is in a ready condition. When this light is off, the printer is interlocked until completion of the print operation.

10

'.INTE. CHECK

• UN

MINU •

DISPlAY

KEAD

INTEnOCK

PUNCH

INTIILOCK

MOCfSS

CHECK STOP

Q)

I/O CHECK

~

Figure 5.

IBM

1401 Auxiliary Console

E 9

Customer Engineering Diagnostic Panel

The customer engineering diagnostic panel (Figure 6) is operative with the tape unit select switch. This switch on the 1401 console

must

have the correct unit selected when the diagnostic panel is used.

/

~DlY

CTR

512

0

2560

128

0

640

32

0

16

0

80

40

20

10 o

0

RC WC o

0

RD WD o

0

ROD WOO o

0

R W

RD WR

ClK ClK

IQfO

O~O

D

0

2

0

O~o n

VALIDITY CHECK

0 0 0

SKEW A REG VRC o

ECHO

B

REG o o o o o o o

A

REG LRCR o

0 lP GO o

0

CKC

BKSP

o

ERROR o

WTM o

DISC o

BKWD o

ERASE

R/W o o o o o o o

Indicator Lights

DELAY COUNTER

These lights indicate the setting of the delay counter.

RC

This light indicates that the read condition latch is on.

RD

This light indicates that the read delay latch is on.

RDD

This light indicates that the read disconnect delay latch is on.

R

This light indicates that the read only latch is on. we

This light indicates that the write condition latch is on.

WD

This light indicates that the write delay latch is on.

WDD

This light indicates that the write disconnect delay latch is on.

W

This light indicates that the write latch is on.

PARITY

EVEN~

ODD~

READ

@

REWIND

@

WRITE

~

RESET

@

ERROR

STOP

@

ERASE

@

MANUAL DISC

@

WRITE W!GAPS

•

WRITE.

CONT!NUOUS

WTM

READ 1 RECORD

•

• READ

CONTINUOUS

\ V

Figure 6. Customer Engineering Diagnostic Panel

)

I

Physical Characteristics 11

READ CLOCK-WRITE CLOCK

These lights indicate the read and write clock settings.

B REG

These lights indicate the character that is in the Bregister.

A REG

These lights indicate the character that is in the

Aregister.

LRCR

These lights indicate which longitudinal redundancy check register

(LRCR) triggers are on.

R/W

These lights indicate the character that is in the read/ write register.

VALIDITY CHECK

Skew:

This light indicates that the skew error latch is on.

A

Reg:

This light indicates an error in read register A.

VRC:

This light indicates a vertical redundancy error in the

R/W register.

Echo:

This light indicates that the echo error latch is on.

LP

This light indicates that a tape unit is at load point

(LP latch on).

It will not go off until the end of a read or write operation.

GO

This light indicates that the

GO latch is on.

DISC

This light indicates that the disconnect latch is on.

CKC

This light indicates that the check character latch is on.

BKSP

This light indicates that the backspace latch is on.

BKWD

This light indicates that the backward latch is on.

ERROR

This light indicates that the

TAU error latch is on.

WT~1

This light indicates that the write tape mark latch is on.

ERASE

This light indicates that the erase latch is on.

Switches

See Figure 6.

PARITY (EVEN -ODD)

This switch activates and controls parity checking.

READ

This switch starts read operation on either read continuous or read one record.

WRITE

This switch starts write operation on write continuous, write with gaps or write tape mark operations.

REWIND

This switch rewinds the tape to load point.

RESET

This switch stops operations immediately.

It also resets error conditions.

ERROR STOP vVhen this switch is

ON, it stops machine on error condition. When this switch is

OFF, the error light comes on but machine continues to operate.

ERASE

This switch turns on erase latch in

TAU.

Erase takes place on next write operation.

MANUAL DISCONNECT

This switch, when

ON for read operation, causes machine to stop at the end of the record.

When

ON for write operation the machine stops writing immediately.

FUNCTION SELECT SWITCH

(5-

POSITION)

Write Continuous:

The select switch in this position sets up conditions to write tape continuously. The write switch must be operated to start writing.

Write with Gaps:

The select switch is set in this position for writing short records.

Write Tape Mark:

With the select switch in this position, one tape mark is written each time the write switch is operated.

Read One Record:

With

READ ONE RECORD selected, one record is read each time the read switch is operated.

Read Continuous;

\"1 ith

READ CONTih"UOUS selected and the read switch operated, the machine reads tape until it is stopped by

MA~UAL DISCONNECT or

RESET.

BIT SWITCHES:

1, 2, 4, 8,

A, B, C

These seven switches control the corresponding bit lines.

12

Power Requirements

The

IB:\I

1401 requires a 3-phase, 208/230-volt, ac source of \'oltage. The mainline voltage is fed through circuit breakers and a contactor to two ferroresonant regulators, a step-down transformer, and a -60-volt supply. In stage

II systems, the mainline voltage is also fed to the ±3-volt marginal check supply.

The

IB:\I

1401 models A, B, C, E, and F are used in systems that also include the

IB:\I

1402 Card Read-

Punch. For all five models, the main contactors, circuit breakers, 12.S0-watt ferroresonant regulator, step-down isolation transformers, -20-volt supply, -6.o-volt supply, and the ±.3-volt marginal check supply are located in the

IB~1

1402 Card Read-Punch. When the

1401 is desired individually, the 1401 model D must be utilized because it contains all the previously-mentioned components.

The 1401 models B, C, D,

E, and F also contain a

585-watt ferroresonant regulator to supply regulated ac to additional SMS (Standard Modular System) power supply assemblies required in these models.

The 1250-watt regulator provides power to the following 1401 model supplies:

-6 \' de at 12 amps

+6 v de at 16 amps

-12 \' de at 20 amps

-20 v de at 15 amps

(-20 v de at 6 amps for model D)

--:-30 v de at 4 amps

(+30 v de at 7 amps for stage II machines)

:±:3 v

Me supply

(stage I machines only)

A

+

12-volt de is developed from the +30-volt supply. A transistor-emitter follmver circuit is used to maintain a constant output voltage. A potentiometer in the voltage divider network can be used to raise or lower the output voltage.

A

+ 18-volt differential (stage

II machines only) is developed from the +30-volt supply. The output voltage of this supply is maintained at 18 volts less than the output of the +30-volt supply. A potentiometer in the voltage divider network is used to adjust for the

18-volt difference.

The .S85-watt regulator provides power to the following 1401 model B, C, and D supplies:

+6 v de at 12 amps

-6 v de at 8 amps

-12 v de at 12 amps

-36 v de at 2 amps

A self-contained unit provides for the printer:

-60 v de at 10 amps

The portion of the +6-volt and -12-volt output that controls transistor base circuitry is distributed, through a switching assembly to the proper pins of the S.MS card sockets. By proper manipulation of the

~IC switches, the +6m or -12m voltages may be varied by the marginal check unit.

In addition to the preceding, mainline voltage is also furnished through a separate contactor to a step-down transformer that supplies 115-volt ac to the service outlets and blower motors.

Signal Levels

Complemented transistor diode logic (CTDL) levels are used in the

IB~1

1401. These are either +T (+6 volts or - T (-6 volts) with a ground reference; or

+ U ( ground) or U (-12 volts) with a -6-volt reference.

A line driver (Figure 7)

IB:\I part number 370089, is used to drive all 1401 output lines to the attached

I/O unit. This line driver has a + U input and a -C current output signal. The -C current output serves as an input to a line tf~rminator,

TR"M part nllmher 370145, or other compatible terminator located in the I/O unit.

C level is essentially a current shift between driver and terminator in which the negative shift is considered the

ON

or logical one condition. C level swings around a ground reference from a +6-volt up level to a

-5-volt down level. \ilaximum permissible ground shift between driver and terminator is

±Y4

volt. The line driver output is a C signal level.

Transmission lines of 93-ohms impedance (range 91 ohms to 105 ohms) are required between driver and terminator. These can be either tVlisted pair or coaxial.

Conversely, lines originating in the 1/0 unit and

Ser\ling as inpllts to the 1401 lTIUst llse t11e same

()f

compatible) line driver as the 14.01, because the 1401 also uses the previously mentioned line terminator.

Signal Levels 13

Input

I

Output Signal Lines

IBM 1401 Output Lines to the I/O Unit

All the following are not necessarily used by anyone machine. They are connected as needed to perform the desired functions. The cable reference number is

02TD. Plug connector location conforms to the following convention: 02TD-121 (signal wire) /122 (reference wire).

PC-059/060

-C

1401 is Stopped

This line has a ·-C level when the delta process latch in the 1401 is off, and the 1401 is not executing an I/O operation. This is an indication to the 1/ 0 unit that the 1401 has been stopped by:

1. executing a stop instruction

2. pressing the stop key in the 1401

3. automatically stopping on an error condition.

PC-084/085

-C

1401 Not Start Reset

This line has a -C level or a +C level at all times except when the 1401 start reset key is pressed. The

I/O unit determines which level is desired and cable connectors should be wired accordingly.

Line Driver

IBM Part

#

370089

PC-095/105

-C

I/O Process Check

This line is at a -C level when a process check

(Bregister, A-register, arithmetic, inhibit, Op-register, or star error) exists in the 1401. This line can be used to stop the I/O unit.

It

notifies the I/O unit that the 1401 will stop at the completion of the I/O operation. If not in an I/O operation, it means that the 1401 is stopped with an error.

PC-101/102

-C

I/O Time 000-030

This line is at a -C level from 000-030 time of every

1401 clock cycle.

PC-103/104

-C

I/O Time 030-060

This line is at a -C level from 030-,060 time of every

1401 clock cycle.

PC-ll0/120

-C

Reset Transmission Error Latch

This line will have a -C level from 090-000 time of one cycle on a BRA~CH ON I/O TRANSFER 1 (error) instruction if the

I/O

transfer 1 line is at a -C level.

PC-115/125

-C

Select I/O Attachment

This line is at a -C level when the 1401 is executing an instruction selecting the I/O unit. At all other times

Line Terminator IBM Part' 370145

+6M

+6V

11k

034$

~+u

~

56uh t

15k~

I

>

680

A

I 1

-12M

-12V

-I2V

Figure 7. Line Driver and Terminator

14

this line is at +C. This line comes on at 090 time of

I-ring

2 of the I/O instruction, and remains on until

I -ring Op time of the next instruction.

PC-119/118 -C Service Response

This line has a -C level from 030 time until the turn on of the service request line, or until the turn off of the service request line, if so required during an I/O read call. It also has a -C level from 075 time until the turn on of the service request line, or until the turn off of the service request line, if so required during an

I/O write call. This line signals the I/O unit that the

1401 has taken the input data when the 1401 is reading, or that the 1401 data is available to the I/O unit when the 1401 is writing.

PC-121/122

-C I/O Attachment Write Call

This line has a -C level when the 1401 is ready and waiting to write and when it is sending data to the

I/O unit. This line comes on at 090 time of the last

I cycle of a

MOVE or

LOAD instruction and remains on until I time of the next instruction.

PC-123/124

-C I/O Attachment Read Call

This line has a -C level when the 1401 is ready and waiting to read, and when it is reading data from the

I/O unit. This line comes on at 090 time of the last

I

cycle of a

MOVE or

LOAD instruction and remains on until I time of the next instruction.

PC-126/127

-C

I/O Time 090-000

This line is at a --C level from 090-000 time of every

1401 clock cycle.

PC-136/137 -C I/O Disconnect

This line is -C when the 1401 reads a group-mark, work-mark from storage when the select I/O attachment line is on. This causes the 1401 to stop writing or reading and advance to the next instruction. This signal is an indication to the I/O device that the transmission of data is completed as far as the 1401 is concerned, and the next instruction is now executed. For certain I/O units this becomes a dc level that must be reset by the I/O transfer 5 line from the I/O unit. This wiring is accomplished in the cable connector.

-C I/O Select Lines

There are a maximum of 16 I/O select lines that are available to send signals to the I/O unit.

The select lines 1 through 14 are controlled by the stacker select (K) Op code with modifier characters

A through N.

The last two select lines, I/O unit 1 control and I/O unit 2 control, are controlled by the unit control (U)

Op code that selects the I/O unit and has modifier characters E and D respectively. pc#

Line

142/141

144/143

146/145

148/147

150/149

152/151

154/153

140/155

138/139

156/157

158/159

160/161

162/163

130/131

164/165

166/167

Active when following instnrction is executed

KA

KB

KC

KD

KE

KF

KG

KH

KI

KJ

KK

KL

KM

KN

U(AAA)E

U (A_AA) D

-c

I/O 1 Select

-c

I/O 2 Select

-C I/O 3 Select

-C I/O 4 Select

-C I/O

5

Select

-C I/

0 6 Select

-C I/O 7 Select

-C I/O 8 Select

-C I/O 9 Select

-C I/ 0 10 Select

-c

I/O 11 Select

-C I/O 12 Select

-c

I/O 13 Select

-c

I/O 14 Select

-c

I/O Unit 1 Control

-C II 0 Unit 2 Control

-C

1/

0 Output Lines

There are seven I/O output data lines from the

IBM

1401. They consist of the 6-bit BCD code plus a check bit. These lines have a -C level from 060 time to 090 time, when they contain information and the 1401 I/O write call line is on. These lines are fed from the Bregister in the 1401. The B-register is reset from 000-

015 time and set from 000-030 time. The information can be taken from the I/O output lines by the I/O unit after .060 time of a 1401 cycle.

PC#

186/187

188/189

190/191

192/193

194/195

196/197

198/199

Line

-C I/O Output 1

-C I/O Output 2

-C I/O Output 4

-C I/O Output 8

-C I/ 0 Output A

-C I/O Output B

~C

I/ 0 Output C

The following output lines go to the 200-position connector located in the 1401, but these lines

do not

have cable drivers connected to them. These lines are intended to be used for completing circuits within the

1401 by jumpering through the cable connector that is connected into the 1401. The jumpering must be located immediately inside this connector and cannot be done in the I/O unit itself.

The first ten lines described here are to be used to enable the 1401 to select the proper I/O device connected to it. The seiected address of the device takes the form of:

%N 1

The character U can be an)l of the follovving charac-

ters;

A

D

E

G

H

I

K o

P

Q

R

S

V

W

X y

Z

Input/Output Signal Lines 15

The other alphamerical characters not listed in the preceding are used by other devices that do not necessarily use the I/O adapter.

The character that selects the I/O unit is located in the A-register at I ring 2 time and these lines must be jumpered in the I/O cable connector to correctly select the device as follows:

PC-Ol7

PC-OI8

PC-OSI

+U A-Reg AB

+U A-Reg A Not B

+U A-Reg B ~ot

A

One of the preceding 3 lines must be jumpered to the input line

+

U A-Reg Sell (001).

PC-044

PC-0l6

PC-035

PC-032

+U A-Reg 12

+U A-Reg Not 12

+U A-Reg 1 Not 2

+U A-Reg 2 Not 1

One of the preceding 4 lines must be jumpered to the input line +U A-Reg Se12 (002).

PC-OS3

PC-034

PC-045

+U A-Reg Not 48

+U A-Reg 4 Not 8

+U A-Reg 8 Not 4

One of the preceding 3 lines must be jumpered to the input line

+

U A-Reg Sel 3 (003).

PC-019

- T Force Odd Red 1-0ut

If the 1/ a unit is sending or receiving data that has an odd-redundancy parity, then this line must be jumpered to the input line - T Force Odd Red PC-004. in the 1401 during an

L 0 read or \vrite operation, then this line must be jumpered to the input line -T

I/O Trans EaR (012).

PC-027

- T I/O Trans 2

If the I/O unit requires that the I/O Trans 2 input line is to cause an end-of-transmission condition to occur in the 1401 during an

I/O

read or write operation, then this line must be jumpered to the input line

-T I/O Trans EOR (012).

PC-036

+6

Volts

This line must be jumpered to the input line T

L ()

Trans EaR, if neither one of the preceding two lines

( - T I/O Trans 1 or - T I/O Trans 2) are connected to it.

PC-014

+U

I/O Disc Out 1

If the I/O unit requires a six-microsecond pulse for a disconnect signal, the line must be jumpered to

+

U I/O

Disc In (030).

PC-015

+U

I/O Disc Out 2

If the I/O unit requires a dc level for a disconnect signal, the line must be jumpered to

+

U I/O Disc In

(location already stated). (It must be remembered that if this condition exists, the I/O Transfer

,5 line must be used to reset the I/O disc latch.)

PC-020

- T Inhibit WM 1

If the I/O input WM line from the I/O unit is being used, this line must be jumpered to the input line - T

Inhibit WM (005).

PC-028

+

U Select lOut

If the I/O unit requires a de level on the I/O 1 Select line, then this line must be jumpered to

+

U Select 1 In

(029). The I/O Transfer 2 line must be used to reset the

I/O

1 select latch.

PC-021

+U

Not I/O Read Call 1

If the I/O unit is sending data from low order to high order, it will require the B-star to modify by minus one, therefore, this line must be jumpered to

+

U Not

I/O Read Call (.006).

PC-022

- T Set Re-address Latch 1

If the I/O unit is using I/O re-address input line, then this line must be jumpered to the input line - T Set

Re-address Latch (007), gated with 030-060 time.

PC-024

+U

Set Write Latch Out

The

IB:M

1401 can accept a pulse to set a latch and hold the I/O Trans 3 condition if this line is jumpered to the input line

+

U Set vVrite Latch In (009).

This latch is reset when the 1401 executes an I/O read call.

PC-023

- T Reset A-Reg Error 1

When it is desired that the I/O unit reset the A-register error if a transmission error occurs, then this line must be connected to - T Reset A-Reg Error (008).

PC-039 +U Start Reset Out

If the I/O unit requires an

ON

signal when the 1401 start reset key is pressed, this lin~. must be jumpered to

+

U Start Reset In (038).

PC-013

-T

I/O Trans 1

If the I/O unit requires that the I/O Trans 1 input line is to cause an end-of-transmission condition to occur

PC-037

+

U Not Start Reset Out

If the I/O unit requires an

OFF

signal when the 1401 start reset key is pressed (and has an

ON

signal at all other times), this line must be jumpered to

+

U Start

Reset In (038).

16

PC-041

+

U Service Request Out 1

If the I/O unit requires the 1401 service response trigger to be turned off when the service request input signal to the 1401 is turned on, then this line must be jumpered to

+V

Service Request In 1 (043).

PC-042

-U

Service Request Out 2

If the I/O unit requires the 1401 service response trigger to be turned off when the service request input signal to the 1401 is turned off, then this line must be jumpered to

+

U Service Request In 1 (043).

PC-046

PC-047

- T Select I/O Out

-T Select I/O In

These lines must be jumpered for any I/O attachment operation. This sets the I/O select latch.

-C I/O Transfer Lines

From one to eight transfer lines can be sent to the

1401 to be tested by the 1401 stored program, and to cause a program branch. The I/O transfer line 1 is used to indicate an I/O error. All other I/O transfer lines can be used to indicate specific conditions as required by the individual I/O units. The I/O transfer line must be at a -C level during the time the

1401 program executes a test for this particular transfer in order for it to be effective. pc#

Line

086/087

088/089

090/100

097/096

099/098

106/107

108/109

117/116

Tested by following instruction

B(AAA) 1

B(AAA)2

B(AAA)3

B(AAA)4

B(AAA)5

B(AAA)6

B(AAA)7

B(AAA)8

-c

1/

0 Trans 1 (Error)

-c

1/

0 Trans 2

-C I/O Trans 3

-C I/O Trans 4

-C

1/

0 Trans 5

-C

1/

0 Trans 6

-C

1/

0 Trans 7

-C I/O Trans 8

PC-048

- T Force Odd Red 2

This line must be jumpered to -T Force Odd Red to force an odd redundancy when -C I/O Trans 8 is brought up during an I/O attachment read or write call.

PC-OSO

PC-OSl

- T I/O Write Call In

-T

I/O Write Call Out

These lines must be jumpered together to enable the clock to start on the first I -cycle when the attachment write call line is brought up.

I/O Unit-Input Lines

to

the IBM 1401

PC-091/092 -C End of Transmission

This line should go to -C to indicate the end of the message being sent to, or being received from, the I/O unit. During an

IR\1

1401 read operation the I/O unit can bring on this line after it has received the service response signal from the 1401 for the last character that it sent. This line must remain on for a minimum of twelve (12) microseconds to terminate the read operation. During a 1401 write operation, if the I/O unit brings on this line the 1401 stops writing and goes to the next instruction. This line must remain on for a minimum of eighteen (18) microseconds to insure terminating the write operation.

PC-OS7/0S8 Emergency Off Switch

Two lines go from the cable connector in the 1401 to the emergency off switch in the 1401. They connect to a normally closed contact on the emergency off switch in such a way that this circuit is open if the emergency off switch is pulled. Otherwise, a completed circuit exists between the two cable connector pins. The I/O unit must use these two pins to connect into their power control circuits. This will enable the 1401 emergency off switch to cut power off in both the I/O unit as well as in the 1401, if this switch is pulled.

PC-093/094

-C

I/O Re-address

When the -C level is available, it sets the re-address latch in the 1401, thus preventing the 1401 from changing its storage-address register, This causes the next storage address to be the same as the last address that was read out of storage. The re-address latch is reset from 030 to 045 time of the 1401 cycle. The latch must

be set from 030 to 060 time of the 1401 cycle in \vhich

re-addressing is required.

PC-082/083 -C Single Character Transmission

This line cannot be brought up before service request comes up.

If the I/O unit holds this line at a -C dc level during a read or vv"rite operation, the 1401 sends or receives only one character and then goes on to the next instruction. The exception to this is, if during a load operation a word separator is received from the

I/O unit or a word separator character is being sent to the I/O unit, then the 1401 sends to or receives from the I/O unit a total of 2 characters.

PC-113/114

-C I/O Service Request

This line has a -C level when the I/O unit requires service, that is, if the I/O unit is ready to send a character of information to the

IBM

1401, or if it has

received a character and is ready to receive the next

character.

Turning on this line sets a trigger

(if the I/O selecting unit line is on), which is used to start the 1401 clock. This trigger is reset by turning on service response in the 1401 or by turning off the I/O select unit line from the I/O unit. This line must go to +C for a

Input/Output Signal Lines 17

minimum of two microseconds before this trigger can be set again.

PC-132/133

-C

I/O Selecting Unit

This line has a -C level when the I/O unit is either sending or receiving data from the 1401. When the

I/O unit turns off this line, the service request trigger in the 14'{)1 is held off and cannot accept a service request signal.

PC-134/135

-c

I/O Attention Light

When this line is held at a -C level the

EXT I/O light on the

IBM

1401 Console lights up, indicating that the

1/0

unit requires service.

PC-168/169

-C

I/O Load

This line is to be held at -C to cause the 1401 to start executing a load instruction and to begin receiving data from the I/O unit. This line is to be used only to start an operation when the power is on in the 1401 but it is not operating, and when the process check is not on. Bringing on this line causes the 1401 to go into an I/O read operation, and to load information into 1401 storage, starting at location 001. At the completion of this read operation, which must be terminated by the I/O unit bringing on the end-of-transmission line, the 1401 transfers to address 001, and executes the instruction located in 001.

The I/O load line must be held

ON for a minimum of thirty (30) microseconds and must be turned off before the first character of data is received by the

1401. This line cannot be used unless the 1401 system is a tape system.

-C

I/O Input Lines

There are eight I/O input lines into the 1401. They consist of the 6-bit BCD code, a check bit, and a wordmark bit. pc#

170/185

172/171

174/173

176/175

178/177

180/179

182/181

184/183

Line

-C I/O Input WM

-C I/O Input 1

-C I/O Input 2

-C I/O Input 4

-C I/O Input 8

-C I/O Input A

-C I/O Input B

-C II 0 Input C

These lines have a -C level when they contain information to enter the 1401. The 1401 enters this information into its A-register during 000-030 time of a Bcycle when the I/O unit is sdected and the I/O attachment read call line is up.

Information relative to signal levels, input/output signal lines, and signal line functions for the

IBM

1402

Card Read-Punch,

IBM

1403 Printer, and

IBM

729 Magnetic Tape Units (as used in the

IBM

1401 Data Processing System) is available in OEM manuals for these machines.

For the purpose of this manual, only the 1401 external cable layout (Figure 8) and plug connector locations of the input/output signal and power lines to these machines from the 1401 are illustrated (Figures

9 through 17).

Connector Receptacle

Pin Assignments

This section contains diagrams of signal and power connectors from the 1401 process unit to the

IBM input-output machines commonly used in the

IBM

1401

Data Processing System.

18

MODEL BAND C

4 CABLES TO 1402 r-----------~~-'

DC POWER r-------------I--i'

AC POWER

;

SIGNAL

'2

SIGNAL

11

MAIN POWER INPUT

(MODEL D ONLy)

T

6

SIGNAL

POWER

~---

I/O ATTACH SIG CABLE

SIGNAL

12

~~---------.

POWER ~H---------,

SIGNAL

'

FRONT

MODEL B, C, D

3 CABLES TO 1403

.. rdbdb'

N

...J

«

Z

£2

V) ffi

~

U

0

~ u

.....

...J

«

C)

«

Vi

..

1402

FRONT

. "

~

0

Z

-4

~

S

-~N

. . W . .

...J~...J

«0«

ZQ.,Z

C)

C)

Vi

Vi

LENGTH OF

CABLE

11FT

15 FT

18 FT

CARD READ PUNCH CABLES

MODELS B & C

AC POWER

DC POWER SIGNAL

11

SIGNAL

'2

479942

480625

480632

479943

480626

480633

479940

480623

480630

479941

480624

480631

CABLE

GROUP

480817

480818

480819

I

LENGTH OF

CABLE

POWER

8FT

480622

11 FT

480629

16 FT

*

14 FT

480636

- -

**

729 II IV

535098

PRINTER CABLES

MODELS 8, C & D

SIGNAL

'1

SIGNAL

12

480620

480627

480634

- -

535099

480621

480628

480635

- -

- -

*

POW ER CABL E SAME FOR ALL MOD ELS

**

MADE TO ORDER, DEPENDING ON NUMBER OF

729

1

5.

TOTAL LENGTH NOT TO EXCEED 100 FEET.

Figure 8.

IBM

1401 External Cable Layout

CABLE

GROUP

480807

480808

480809

- -

- -

. "

~

0

Z

.....;

'-I

~

0

~

SIGNAL

=

POWER

SIGNAL

POWER

<: tMlN

POWER

- -

- -

- -

609544

- -

I

0

Z

-4

J

'-I to.)

SIGNAL

0

'0

=

POWER

0

~

SIGNAL

POWER

<:

~

I

I

_1

TO NEXT

TAPE DRIVE

19

15

1-0

+U

+U

1-0

Disc

Out 2

Disc

Out 1

-T

1-0

-T

1-0

Trans 1

Trans

EOR

30

+U +U +U

1-0

In

I

Select Select i

Disc I 1-ln

1 Out

I

-T

1-0

Trans 2

45

+U +U

-U

+U

I

A Reg A Reg Serv

8 Not 4 12

Serv

I

Req Req

I

In

~

*

""'~1

St+~

I

I is i

-9""

"",J

I ""-En erg

*

Off

Out 2

-I

I

I i

75 i

I

I

+U

Serv

Req

Out 1 i

I

-C" "'"

""S-i! gle

-C

Cha

~

"'"

I

+U

Set

Error

Lat In

+U

Set

Error

Lat Out

81

+U

!

+U

8

-T

Set

Read

Lat In

I Set Reset

-T

Set

I

+U

! -T

Not I/O i

Inh

I Write A Reg

Readr

I Read

Lat In Error Lat

Coli i

WM

+U

I

+U

Set . Set

~:set

;T[

Read i

Write

Reg

Lat Out, Lat Out

Error 1

-T

Set i

+U

I

-T

Not

1-0 i Inh

Readr I Read i

I

Lat 1

I

Calli i

WM 1

-T

Force

+U

A Reg

Odd Sel3

I

Red

-T

+U

I

I

Force

A Reg

I

Odd

A Not B

Red 1

I i i

+U

Start

Reset

Out

+U

A Reg

Sel 2

+U

A Reg

AB

1

+U

A Reg

Sel 1

16

+U

A Reg

Not 12

I

38

+UI

Start I Not

Start~

Reset

+U .1

I

Reset Ou

: 53

In

I i

I i

+6V

-Ti

I-O! 1-0 I

Write Cad Write CaJj

Out'

+U

I

+U +U

A Reg i

A Reg i

A Reg I

1 Not 2! 4 Not 8

-Ti

I

I

Not 84

I

I

I

I

In

I

·T

!

I

Force

I

Odd

2

Red

I~

I

I

! i

I i

I

I

+U

A Reg

2 Not 1

Sel

1-0

In

-T

80

31

+U

A Reg

B Not A

46

Sel

1-0

Out

-T

61

I

106

-C

1

12~

-C

156

Figure 9.

IBM

1401 I/O Attachment Plug Connector Receptacle (Connector Side)

20

r

1

I

PM

I

1

+U

16

PM

2

+U

PM

3

+U

PM

4

+U

PM

5

+U 8

23

1

31

I

I

46

61

I

I

176 +UI

PM

I

I

76

I

86

I

PM

77

+UI

I

I

I

I

(olum

PM

78

+U

,

I

I

PM

I

+U180

I

I

79

PM

80

+U

I

I

I

,

I

!

I i n

I tc 80

Puncl

~ Ma~

I

38

53

I

68

I I

netsl

(+u~

81

Punch

Brush

, 1

I

I

Punch

Brush

' 2

90 91

I

15

30

45

60

75

,

Punch

Brush

'3

Punch

Brush

, 4

85

Punch

Brush

# 5

95

I

I

96 105

100 101

piC

I I

I

I i

I I I I

115

,106 i

I

I

116

110

I

I

I

120

I

111

121

125

I

I

I

126

I

,

I

I

I

141

I

! i

I t i

I

156

Punch

Brush

# 76

171

186

I

Spare

I

I

Punch

Brush

1177

Punch

Brush

, 78

I

Punch

I

Brush

I

#79

-u! i

I

I lnt,'

I

Reset i

After

9

Cam

I

I X,;'I

Spare

I

+U

Stack

Brushes

Inh

I I

-T

I

133

Cc

lumn

I to

~O

P

~nch

Brus 'les

I

Punch

Brush

#

80

Pun,h

-T

Scan

CB

+U

Punch

Check

Light

Start

Relay

Spare

148

163

I

I

'ond,

Stop

-T

I

Pund,

Clutch

Magnet

-T 178 -T

~o,

I

I Punch

I

-T 193

-T

Punch

I

Pun,h

Jam

I

-T!

I

+TI

I

I Check

Reset

I Die

CL

Punch

I

Delay

-T

I

I

I

I

-T

Stacker

Latch

Reset

I

I

I

140

155

170

Stack

4

+U 185 +U

I

S~"

I

200

1

I

I

I

Figure 10.

IBM

1401 to

IBM

1402 Punch Connector Receptacle (Wiring Side-Fixed Mount)

I

21

15

I

I

30

45

60

I I

1

8

23

I

I

1

Read

Brush

, 5

111

Read

Brush

' 4

38

Cor

~nectt

)r

Pir

IS

1-

~O

N rush

I

~s

Co I.

I-e

0

53

, 1

Read

Brush

, 3

I

/I

i

Read

Brush

' 2

11

If

1

Read

Brush

I 1

16

I

I

I

I

I

31

46

I

75

I i

85 , 2

95

Read

Brush

'5

I

I i

I

' 2

Read

Brush

' 4

105

I

I

115

'2

Read

Brush

' 3

I

'2

Read

Brush

1f2

I

81

'2

Read

Brush

' I

191

I i

I

I

I

I

I

101

1

I

I

III

68

RiC

61

I

80 I

I

Read

Brush

If

80

190

I

I

100

, I

Read

Brush

'79

!

I

I

I i

I

I

' I

Read

Brush

'78

110

, I

Read

Brush

'77

!86 i

I

1

I i

96

76' I

Read

Brush

, 76

I

I

I

106

125

140

I

120

121

I

133

Con nectc

r

Pil1 s

81-

~160

No.2

Rea~

Bru

~hes

~01.1

~80

148

116

126

141

155

163

185 +U

Stack

2

1200

I

170

-T

Read

Clutch

I

!

I

I

1

Load

Key

-T

Read

Stop

-T

I

+U

Stack

I

+U

Invalid light

+U

I

Read

Check light

I

I

2

CLC

+U

J

I

I

Key

On

-T 178

+T

Start

+T

Read Stop

Key

I

Stacker

On Reset

Stack

-I

193

I

Spare

Select

I

Spare

Spare

Start

+T

160

#

2

Read

Key

Brush

N/C

180

Last

Card

-T

Spare

Inlk

Stop

+U

'2

Read

Brush

I 79

RE':Jd

+T

Check

Reset

'2

Read

Brush

, 78

Read

Jam

-T

' 2

156

Read

, 2

Read

Brush

'77

Brush

, 76

Not

-T 171

Proc

Feed

PrQ!::

Feed

-T

1/2 Write

I

2

Brush

I

I

1/2 Write

# I

Brush

I

I

I

B h .

1m rus p

CB

I

CB

Reset

-III&!

I

Read

Camp

Gate

-TI

I

I

Figure 11.

IBM

1401 to

IBM

1402 Reader Connector Receptacle (Wiring Side-Fixed Mount)

22

PWB PWD

WIRING SIDE

PWC

CON'

1

2

3

4

5

6

7

8

CONNECTOR PVVA

WIRE SIZE FUNCTION

14

8

14

8

8

14

8

14

133V AC Bulk Supply

Spare

133V AC Bulk Supply

208V AC

~1

Tape Drive

208V AC jf2Tape Drive

RiP

Frame Ground

208V 93 Tape Drive

Spare

CON

I

5

6

7

8

9

1

2

3

.4

CON'

8

9

10

5

6

7

11

12

13

14

15

16

17

1

2

3

4

CONNECTOR PWB

WIRE SIZE

FUNCTION

16

16

14

14

14

10

10

16

16

16

16

16

16

16

16

16

16

3V Control

3V Control

Emergen cy Stop

Carri_c::Ige Motors- 208V

~2

Carri age Motors- 208V ¢2

Chain

&

Rib Mtrs 208V 12

Chain

&

Rib Mtrs 208V ¢2

3V Control

3V Control

3V Control

Power On Switch

Power On Switch

Spare

Spare

Conv Outlets-115V AC

115V

AC Common

Blowers-115V AC

15

16

17

Figure 12.

IBM

1401 to

IBM

1402 Card Read-Punch Power Plug Pin Assignments

CON'

1

2

5

6

3

4

7

8

9

10

11

12

13

14

16

16

16

4

4

16

16

16

10

CONNECTOR PWC

WIRE SIZE

FUNCTION

Chain Interlock

Chain-Relay Pick

-12 Volts DC

-60V DC Common Ground

-60V DC Common Ground

Chain Intlk

6 Volts DC

Space Magnet OFF

-20V Seq-Mem Return

CONNECT~

PVVD

WIRE SIZE

FUNCTION

14

4-

16

16

16

16

8

10

10

8

4

14

16

16

16

16

16

Spare

-60V

Se~

Printer Mags

Marginal Check

DC Common Ground

Spare

Marginal Check

-60V Seq Printer Iv\ags

Spare

-20V Sense Control

=

12 Volt Sense

Power Hold

I

Printer Intlk Ctrl 1

Printer Intlk Ctrl 2

I

SkiD Iv\agnet Off Relav ilntik

Space Magnets

Control

Spare

2.3

H D= Hammer Drive H R

=

Hammer Return

H D

=

Hammer Drive H R

=

Hammer Return

H R

9

&

11

HD

9

HD

7

14

HR

1

5 & 7

I

I

HD

5

HD

3

HR

1 & 3

HD

1

HR

10& 12

HD

10

HD

8

H R

6&8

4

HD

6

HD

4

H R

2&4

HD

2

HD

21

HD

19

1

I

HR

I 17 & 19

HD

17

II

I

HD

15

HR

13 & 15

HD

13

H D

11

16

HD

20

HR

18&20

HD

18

IT2

HD

16

HR

I

HD

14& 161 14

HD

I

12

HD

31

41

HR

& 4J

HD

53

H R

I

29 & 31 i

H D

41

HD

51

H D

29

HD

39

HR

49 & 51

H D

I

H R

27125&271 i

I

H R

I

I

37 & 39

1

1

H D

I

49

I

!

HD

37

HD

47

HD

25

HD

35

HR

45 & 47 i

HD

23

HR

33 & 35

HD

45

17

HR

21 & 23

25

H D I

J3

I

33

~I

I

24

32

40

HD

32

HR

42&44

HD

54

HR

30&32

HD

42

HD

~

HD

30

HD

40

HD

28

HR

38&40

HR HD

~&~ ~

HR

1 26& 28

1

1

20

28

36

H D I

38

HD

48

I

HD

26

HD

36

HR

~&48

HD

~

17

1

II

I

I

H D

24

H R

34&36

HR

1

1 22&24 I

25

J

I

HD I

34

I

33

I

HD i

44 i,

41

1

I i Spare

I

HD

63

49

56 52

HR

I

I

73 & 75

H D

73

I

H D

I

71

HR

69

&

71

I

HD

69

HD

67

HR

65 & 67

H D

65

HR

74&76

HD

74

HD

72

HR

70&72

HD

70

HD

68

HR

66&68 i

!

57

64

!

94H.~

I

60

HD HD

I

HR

HD HD HD H D

H R

I

HD HD

H R

HD HD H D

85

83 181 & 83

!

I

81

79

77 & 79

1

77

75 I

86 84

82&84

82 80 78

I

1

J

72

72 68 i

HD

95

1

I

I

HR i

93 &95:

I

HD

93

HD

91

HR

89 & 91

HD

89

I

HD

87

HD

96

H D

I

94 I

HD

92

H R

90&92

I

I so

HR i i HD

I

1 105 l

I

188

'96

H D

I

117 i H D i 127

!

I

HD

115

I

I

, HR

I

1125

& 1271

76 73

80

I

I i

HD

103

, HR

1113

& 115

H D I

H R

1

H D

!

H D H R

1

H D

I,

101&103101 199 :97&99 9 7 ,

I :

,81

HR

106& 1081

88

84

HD

I HR

HD

I

HD HD

HD

I

113

III

1109 &

1111

109 107

118

I

I

I

92 !89

96

H D

I

H R

!

1

HD

HR

I

HD

I

125 I

123 121 &

1231

121

I

119 1117 & 119

1

~~

H D

116

H D

II

H R

128 126&128

I

I i

H D ' H R

104

1

HR I

114& 116

HD

1

I

102 &104

HD

114

126

!

HD

124

1

76

84

92

H D

102

HD

I

112

HR

122 & 124

'I

HD

90

HD

100

HR

I

I

1 i 88 i

1110&1121

I

HD

122

II

H D

H R

98&100

HD

110

HD

120

104 j i

HR

I

I

I

Spare

I i

HD

61 & 63 I 61

HD

59

Spare

HR

57 & 59

100

Spare

I

!

I

HD

57

HD

131

1

HD

55

HR

I

HR

53 & 55

197

I HD

129 & 1311 129

HD

104

64

1

HR HD

I

62&64 62

I

Spare I

Spare

Spare i

HD

60

Spare

58&60

100

HR

Spare

HD

58

HD

132

1

HD

I

56

H R

I

!

130& 132

1

49

57

65

81

HR I

54&56

J

HD

66

HD

76

H R

I

I

86&88 i

J

1

73

I

H D I

98

HD

89

108 I

J

130

J i

!

I

'I

I

HR i

118 & 120

II

97

J

'

H D

I

:112

!

108

!105

112 108 105

! 11

II

Shield

Gnd

II

Shield

Gnd

Spare

'1-

20 Volts I Spare

, D C

I

Spare Spare

I

!

Spare

Shield

Gnd

Shield

Gnd

Spare

1

I i

Spare

I

Spare Spare

I

Spare

I

1

120

1

I

113

+U

Hi Spd

+U

Lo Spd

+U

+U +U

120

116 113

-T

Forms Hi Spd Lo Spd

Spare Spare

Run Mode Stop Ind Stop Ind

1 Spare Spare Spare Spare Spare Spare Spare Spare

Check Start Ind Start Ind

128

Spare

I

Carr

I

Inlk

136 -T

I

Start i Spare

Relay I

Spare

I

Spare

124

DC Gnd

I i

Spare

Spare

121

- 12 Volts

DC

129 -T

End Of

Forms

Chain

Motor

Relay

Spare

144

+T

!

Check

+ 12

Reset

1

1

15~, ~U!

:)Jngle

I

I Cycle r

-T

Sense

I

Sense 140 -6

Amp Amp

II

+6

Volts DC Volts DC I

1-

T

R~tore

2 1 ey

I

I

I

137 +U

Restoi'e

Key

I

I-T

1

148

, - 6

I

I

Stop Key I Volts DC I Volts DC I Spare

1

145

I Spare i

1

I

I-T

I

Space

!

Key

156 +U I +U'

Space

Key

,

1

+6 Not Start Start Ke)

I

Volt. DC Kev

I I

_ m

--I

'I

I

128

Spare

-60v

Ctrld

Print

Conn

Intlk 2

124

Spare Spare Spare

121

Spare

I

J

136

Slow

1144

Stop

Brush

I

3

I

1

152

Stop

Brush

1

11

160 +U

Forms

Check

Ind

Slow

Brush

6

Slow

Brush

5

Slow

Brush

4

132

Slow

Brush

3

Slow

Bn,;sh

1

Slow

I

Stop

Brush

2

Stop

Br~sh

I i

Slow

Brush

12

140

Slow

Brush

11 i

Slow

Brush

10

I

I

Slow

Brush

9

Stop

Bru~h

10

Stop

I

Brush

I

9

I t

Stop

Brush

8

148

Stop

Brush

7

Emitter i

High

I

High 156Low

!

Speed

I

Speed

I

S~ed

I

~top

I

:.tart

I

:.rop

Stop

Brush

6 I

I

1

I

Stop

Brush

5

Low

II

S!,.eed I Spare

I

:.rarr

I

129

137

Slow

Brush

8

145

Stop i

Br~sh

!

Figure IS.

IBM

1401 to

IBM

140S Signal Connector SC-1,

(Wiring Side-Fixed Mount)

Figure 14.

IBM

1401 to

IBM

140S Signal Connector, SC-2,

(Wiring Side-Fixed Mount)

24

PIN

NO

5

6

7

8

1

2

3

4

9

10

11

12

13

POWER PLUG PI N ASSIGNMENTS

PRINTER POWER CABLE

WIRE

SIZE TYPE

VOLTAGE OR CONTROL

AC Outlet 115 Volts

AC Outlet 115 Volts

Bond

-60 Volts

208V 0'1

208V 0'2 Carriage Motor

208V

fJ3

Carriage Motor

I

14

14

14

Spare

Spare

Spare

!

18

208V

~2-

Chain and Ribbon Motor

I

18

208V 0'3 - Chain and Ribbon Motor I 18

Spare

I

I

18

18

18

18

10 i

10

10

I

I

AC

AC

DC

AC

AC

AC

AC

AC

WRAPPER OUTER JACKET

®

((f»

~®(@ o

~

PIN LAYOUT - POWER PLUG

WIRING SIDE

Figure 15.

IBM

1401 to

IBM

1403 Printer

Power Plug Pin Assignments

POWER CABLE

CROSS SECTION VIEW

2.5

15

30

45

60

75

I

I""

*

+P

Set

I

Sta us"

Sel a

~

/ '

.err ~

Pt

+p ..............

./ / +P

~~Wrlte

* /

/ '

-N '- .......

Sel ayJ

Ad Pt

At

/

,

,

-N " "

-N '- ....... +p' '-

+P

.......

1 -N

....... *

-N

* /'

/ '

+ p ' ,

*

Start re~d

Sel a d---T:I.

...-0 f

R;w..lI::d and

Unl~

,

/ ' 23-N

Sel arsl-

/,( n

* /'

/ '

+P

~'" r:I.

, *

53

./ /' +P

'Set and

Rev in~

,

-MtJ~ IV

* /'

/

-N'.......

Seh8J~y and

W lte-,

.........

Sel Olv.!-Rd'y

'- *

. /

'*

'-

*

+ p ' ,

T';;rn Off

T I ....... '-

Sel'aQ~

Read

Of;ly,

Spare

.......

*

+p ....... ,

'TUm .Qn

T I

.......

16

31

Sd'O(~ Rdy

NIod II,

.......

+P

....... " *

+P 46 / '

H~

/ '

I

Shield / ' Per slty

.......

. /

61

68

es .......

, 8V PP

958V PP

/ '

/ 8V PP

/

~acl-Bus

4

/ ./

/ '

/

/

,

8V PP

* /

" "

I

8V PP

*

Read

115 i

Spare

",*

8V

Shield

PP

/ 1

I /

I ' ,

I / /

/

125

Shield Spare

Shield Spare

140

-6V

155

TiC

133

148

+6V

+P

/

. /

.......

,

/~

1

+P

"se.l

~ct

TU 3--.

,

*

76

./ +P

* /

/

1

96 / /'

1 / se~t

/l'U 4

!116

126

141

170

-12V

163

Ground

156

185

200

-N

Wrfte/'

/,...-8u A

/ , / 178 -N

W!jje/

/..-1Iu

8

/ ' / -N

.......

,

* /

-N ....... ,

'w.r. te

Pu

SEf-.....

"

,*

ReM

Wr

Trig e"'- "

* /

* / '

-N m........

W'ritEl~cho

Pul e ,

,

-N

Shield

'-* "

Spare

* /

Shield

Figure 16.

IBM

1401 to

IBM

729 Magnetic Tape Unit Connector Receptacle (Wiring Side-Fixed Mount)

171 / . /

W~te'

/8~

1

Spare

* /

Shield

186

Spare

26

I

PIN

NO

4

5

6

7

8

1

2

3

9

10

11

12

13

POWER PLUG PIN ASSIGNMENTS

TAPE UNIT

VOLTAGE OR CONTROL

AC Outlet - 115 Volts

AC Outlet - 115 Volts

Bond

Spare tv\ode I II & IV Reset - 208 Vo I ts

Spare

Spare

Spare

Spare

Model II

&

IV

Reset -

208 Volts

Unreg AC

~n

Unreg AC

~2

Unreg AC.03

POWER CABLE

WIRE

SIZE TYPE

14

14

14

18

18

18

10

10

10

18

18

18

18

I

AC

AC

AC

AC

AC

AC

AC' o o

POWER PLUG PIN ASSIGNMENTS

WRAPPER OUTER JACKET

POWER CABLE

CROSS SECTION V lEW

PIN LAYOUT - POWER PLUG - MALE

WIRING SIDE

Figure 17.

IBM

1401 to

IBM

729 Magnetic Tape Unit Power Plug Pin Assignments

In Figure 18, the diagonal dotted line connecting pins 082 and 083 indicates that the two serve as a pair; that is, signal wire and reference wire for a given function. Signal level designator

-C identifies connector 082 as the signal wire. An asterisk identifies connector 083 as the shield or reference wire.

Oaa.

082-C

"-

-stn~le

C~ tJr "-

Tre ns

""" of. """

Figure 18.

27

Index

A-Address Register .................................. 6, 9

Addressing System .................................... 6

Address Stop Mode ................................... 9

Alter Mode .......................................... 9

A-Register ........................................... 6

Auxiliary Console Keys, Switches and Lights .. . . . . . . . . . ..

10

Backspace Key .......................................

10

B-Address Register .................................. 6, 9

Bit Display Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

10

Bit Switches .....................................

10,

12

B-Register ........................................... 6

Card Read-Punch Power Plug .......................... 23

Character Display Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9

Checking ............................................ 7

Console Keys and Switches .................... 7, 8, 9, 10

Console Lights ....................................... 10

Core Storage ......................................... 5

Customer Engineering Diagnostic Panel .............. 11, 12

Emergency

Off

Switch .. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8, 17

End of Transmission .................................. 17

External Cable Layout ................................ 19

Force Odd Red I-Out .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16

Force Odd Red 2 ..................................... 17

Function Select Switch ........ . . . . . . . . . . . . . . . . . . . . . . .. 12

Functional Characteristics ............................. 5

Hole-Count Check .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7

I-Address Register ................................... 6, 9

Inhibit WM 1 ......... . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16

Input Lines .......................................... 17

Input/ Output Attachment ............................. 7

Input/ Output Signal Lines ... . . . . . . . . . . . . . . . . . . . . . . . . .. 14

Instruction/Execution Mode ........................... 9

Instruction Format .................................. 5, 6

Instruction Length Light ..............................

10

I/O

Attachment Plug ................................. 20

I/O Attachment Read Call ., . . . . . . . . . . . . . . . . . . . . . . . . . .. 15

I/O Attachment Write Call ............................ 15

1/

0 Attention Light ................................ 18

I/ 0 Check Stop Switch ............................... 7

I/O Disconnect ...................................... 15

I/O Disc Out 1 ....................................... 16

I/O Disc Out 2 ....................................... 16

1/

0 Input Lines .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18

I/O Load ........ ' .......................... " ..... , .. 18

I/O Output Lines ..................................... 15

1/

0 Process Check " . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 14

I/O Re-address .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17

I/ 0 Select Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 15

I/O Selecting Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

I/O Service Request .................................. 17

I/O Trans 1 ......................................... 16

I/O Trans 2 ......................................... 16

II

0 Transfer Lines ................................... 17

I/

0

Write Call In .................................. 17

I/ 0 Write Call Out .................................. , 17

Line Driver

Line

Tenninat~~ . : : : : : : : : : : : : : : : : : : : : : : : : : : ....... .

13, 14

13, 14

Logic Lights ......................................... 10

Manual Address Switches .. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9

Mode Switch .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9

Not I/O Read CallI .................................. 16

Not Start Reset Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16

Operation Code ...................................... 5

Output Lines ......................................... 14

Parity Check ...................................... 7, 12

Physical Characteristics ., . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7

Power Off Key ....................................... 7

Power On Key ....................................... 7

Power Requirements .................................. 13

Printer Display Light ................................. 10

Printer Power Plug ................................... 25

Processing Unit ...................................... 5

Punch Connector ..................................... 21

Punch Interlock Light ..................... , . , ......... 10

Read Continuous ..................................... 12

Read Interlock Light ................................. , 10

Read One Record .................................... 12

Reader Connector ..................................... 22

Reset A-Reg Error 1 .................................. 16

Reset Transmission Error Latch ........................ 14

Run Mode........................................... 9

Select 1 Out ......................................... 16

Select I/O Attachment ................. , .............. 14

Select I/O In ........................................ 17

Select I/O Out ............. ' ...... , ................... 17

Sense Switches ....................................... 9

Service Request Out 1 ................................ 17

Service Request Out 2 ................................ 17

Service Response ..................................... 15

Set Re-address Latch 1 ................................ 16

Set Write Latch Out ...... . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16

Signal Connector SC-l ................................ 24

Signal Connector SC-2 ................................ 24

Signal Levels ........................................ 13

Single Character Transmission . . . . . . . . . . . . . . . . . . . . . . . . .. 17

Single Cycle Non Process Mode. . . . . . . . . . . . . . . . . . . . . . .. 9

Single Cycle Process Mode ............................ 9

Start Key ... '" . . . . . . .. . .. . .. . .. . .. . .. ... ... ... . . . .... 7

Start Reset Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Start Reset Out ....................................... 16

Stop Key ............................................ 8

Storage Print Out Mode ............................... 9

Storage Scan Mode ................................... 9

Stored Programming. . . . . . . . . . . . . . . . . . . . . . . . . . .. . .. . ..

5

Tape Load Key ..................................... 10

Tape Select Switch ................................... 9

Tape Unit Connector ................................. 26

Tape Unit Power Plug ................................ 27

Transmission Lines ................................... 13

.............. 7,

12

Word Mark ........................................ 6, 7

Write Continuous '" ................................. , 12

Write Tape Mark ....... . . . . . . . . . . . . . . . . . . .. . . . . . . . . .. 12

Write with Gaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 12

28

(10-61 :5M-W)

A24-1424-0

TIrn~

~,

International Business Machines Corporation

Data Processing Division

112 East Post

Road,

White

Plains,

New

York