Programming instructions

PERFORATED

TAPE

PUNCH

CONTROL

Info.

Feed + Advance

* TELETYPE

BRPE

Punch

* TAPE

Timing Signal

PUNCH

Figure 23 - Perforated-Tape Punch programming logic

CARD READER AND CONTROL, TYPE 41-4

The control of the Card Reader is different than the control of other input

devices, in that the timing of the read-in sequence is dictated by the device.

Once the command to fetch a card is given, the Reader will read all 80

columns of information in order. To read a column, the program must

respond to a flag set as each new column is started. The instruction to read

the column must come within 300 microseconds after the flag is set. The

interval between flags is 2.3 milliseconds. The commands for the Card

Reader, iot series 67, are:

crsf - 706701 - Skip if Card Reader flag is a 1. If a card column is present

for reading, the instruction will skip.

crrb - 706712 - Read the card column buffer information into AC and clear

the Card Reader flag. One crrb reads alphanumeric in-

formation. Two crrb instructions read the upper and lower

column binary information.

crsa - 706704 - Select a card in alphanumeric mode. Select the card reader

and start a card moving. Information will appear in alpha-

numeric form.

crsb - 706714 - Select a card in binary mode. Select the card reader arjd

start a card moving. Information will appear in binary form.

Upon instruction to read the Card Reader buffer, 6 information bits a ‘e

placed into AC bits 12-17. Alphanumeric (or Hollerith) information on t

card is encoded or represented with these six bits. The binary mode enabl

the 12 bits (or rows) of each column to be obtained. The first read

buff r

instruction transfers the upper six rows (Y, X, 0, 1, 2, and 3), the seconid