IBM System 360 Operating Manual page 38

A cancel operation is executed by pressing the
alternate-code key and the zero key while still
holding the alternate-code key down.
The read inquiry operation is then terminated.
The proceed light is turned off. The keyboard is
locked, a hold condition is placed on Reader 2,
and an automatic carrier return and line feed is
initiated. The cancel character is not transferred
to storage. Programming determines what is done
to the data characters transferred to storage before
the cancel character is generated.
Read-Inquiry Command (with Home Component
Recognition Feature)
With the Home Component Recognition feature
active in the 1051, the read-inquiry command func-
tions as described in the following paragraphs.
Initial Selection Initiated by Start I/O Instruction
Printer 1 (either 1052 or 1053) is automatically
selected for monitoring.
Execution of Read-Inquiry Command
If
the operator desires a different or an additional
output to monitor during the inquiry operation, he
can:
1. Prefix outputs on and off from the keyboard
before entering data, or
2. Put the PROG/DUP switch in the DUP mode
and manually switch-select the desired
monitoring outputs. (He must return the switch
to program mode before entering EOB. )
If the operator presses the home reader Start key
to enter his inquiry from Reader 2, the adapter
continuously tests for Reader 2 select-and-ready
during that portion of the inquiry operation.
End Operation
At the end of each read inquiry command, all 1050
output devices are deselected.
Carrier Return
When operating on-line, if the carrier reaches the
right margin without a carrier return signal from
38
the program, the carrier returns automatically
and a single line feed occurs. Printing is suppressed
during the carrier return.
Off - Line 1050 Functions
Home Component Recognition operates in its normal
manner when the 1050 is operated off-line.
1050 I/O Prefix Selection
Printer 1 Prefix 1
Printer 2 Prefix 2
Punch 2 on
Prefix 4
Printer 1 off Prefix 5
Printer 2 off
Prefix 6
Punch 2 off
Prefix 8
*Ribbon Shift up Prefix A
*Ribbon Shift down Prefix B
*Single- Line Feed
Prefix C
*Double-Line Feed Prefix D
*Requires Automatic Ribbon Shift and Line Feed
Select feature in the 1051.
Note: When the 1050
is
operating on-line, Reader 1,
Reader 2, and Punch 1 are always automatically
selected on.
Operations Terminated by Intervention-Required
If the execution of a command is terminated by an
intervention-required status:
1. An automatic carrier return and line feed is
attempted but may not be executed to monitoring
printers. The carrier may have to be returned
from the keyboard off-line, after the cause of
the intervention-required condition is removed,
and before the 1050 is returned to on-line
operation.
2.
If
paper tape was being read, the paper tape
reader stops within the record being read.
The paper tape must be manually repositioned
after the cause of the intervention-required
condition is removed and before the 1050 is
returned to on-line operation.
3. If cards were being punched or read, the punch
or reader stops within the card being processed.
The cards must be manually released or ejected.