1056 Card Reader-Special Features - IBM 1050 Reference Manual

Automatic Card Reread
This operation requires either the home-correction spe-
cial feature or the line-correction special feature. When
transmitting to the line and an error is detected, this
enables the card reader to reread the card, two more
times if necessary, and retransmit the message in error.
If the message is still incorrect after the third trans-
mission, the reader stops and manual intervention is
necessary. See Home-Correction and Line-Correction
in the section on 1051 Special Features.
1056 Card Reader - Special Features
Card Reader Program
A punched paper-tape loop, physically the same as that
for the 407 tape-controlled carriage, provides a means
of conserving card columns used either for constant
data or for control and instruction codes. This feature
eliminates the need for punching some, or all, of the
control codes in the cards.
Data punched in the tape can also be read, thereby
doubling card capacity (160 columns) if necessary. The
tape and the card move synchronously during the read-
ing operation, a column of the tape and a column of
the card being read alternately, starting with column 1
of the tape. If data is punched in a tape column, as
well as in its corresponding card column, two reading
cycles occur. If the tape is not punched in that column,
only one reading cycle occurs.
Controls and data are punched in the tape (Figure
28) as follows:
TAPE
TRACK
1
2
3
4
5
6
7
8
9
10
11
12
FUNCTION
B-Bit
A-Bit
C-Bit
8-Bit
4-Bit
2-Bit
I-Bit
Prefix
Eject
Data and Function Code Punching
(PTT Code/6)
Field Skip Start
Field Skip Stop
Tape Homing Punch
When the prefix track is punched, its associated
(following) numeric or alphabetic character can be
punched in the same tape column to conserve card
columns. In this case, two tape-reading cycles occur for
that column, and one for the associated card column.
When the eject track is punched, the card being
read is ejected to the stacker and no EOB code is
generated.
Field skipping is controlled by tracks 10 and 11.
Card data is ignored during skipping, but if data is
punched into the tape, it is read and acted upon, in-
cluding data in the skip-start column. A valid character
code must be punched into the same tape column with
the skip stop punch to insure stopping.
Note: This valid character is read and acted upon. If no action
is desired, use an idle or delete code.
When skipping is stopped with an 11-track punch,
the 1056 reverts to normal reading operations; the data
in the corresponding card column is read. Skipping can
also be stopped by an EOB or EOT code in the tape, a
9-track punch, or by pressing the eject button. In these
instances, except for EOB, reading is not resumed, but,
rather, the card is ejected to the stacker. When the
EOB stops the skip, normal EOB functions apply. Re-
fer to Reader Operation-1056 in the Principles of Op-
eration section.
Each program tape must contain a punch in track 12.
This tape-homing punch is used to maintain the proper
relationship between the card columns and their asso-
ciated tape columns. Also, any data punched in this
column is read. Various length cards require this hole
to be punched into the following tape column areas
(refer to Figure 28):
LOCATION OF
CARD LENGTH OF
DATA TRACK 12
LENGTH
TAPE LooP COLUMNS PUNCH
80 col. 81 col. 1 through 80
56 through 80
51 col. 54 col. 1 through 51
29 through 51
22 col.
54 col. 1 through 22 2 through 22
28 through 49 29 through 49
22 col. 81 col. 1 through 22 2 through 22
28-49 29 through 49
56-76 56 through 7 6
With this feature, a switch is provided to enable the
operator to make this feature operative when desired.
Note: Data that is punched in tape columns beyond the last
card column is not read.
51-Column Card Feed (Single Card Feed),
1056 Model 2 Only
This feature provides the card reader with the ability
to feed, read, and stack interspersed 51-, or 80-column
cards.
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