IBM 2790 Manual page 46

(2) accept all data from the 2715 until a response to
'set read deferred data mode' is received (indicates
that the disk is clean of all data), and (3) send X'D
('reinitialize disk') before restarting the 2790 input.
Standard Responses to Control Requests Sent to CE/Oper-
tor Panel Successful completion of a valid panel operator
request is indicated by displaying the transaction control
byte in positions 0-7 and X'FO' in positions 8-15 of the
display register. An invalid panel request is flagged by
displaying X'0001' (unless otherwise stated) in the display
register and setting the red Catalog Number lamp. Invalid
panel requests never generate System/360 response mes­
sages/ Negative responses are indicated by setting of appro­
priate Catalog Numbers.
X 'C V — Bypass Area Station
• Function— Causes a 2790 Bypass command to be issued
to the designated area station, causing it to go off-line.
The response message is printed on the 2740 (if pre­
sent) prior to being sent to the CPU.
• Request F orm at-
System/360— Standard format with dj = area station
address.
CE Panel— Standard format with area station address
entered in positions 8-15 of the Data/Address switches.
• Response Format—
System/360 request:
a. Positive— Standard response, with r
the EBCDIC format of the binary area station address.
b. Negative— Standard response is sent ( ^ and r^ =
EBCDIC format of the binary area station address)
when the designated area station fails to bypass, or
if the area station is not defined.
CE panel request:
a. Positive— Standard response.
b. Negative-Catalog number X'0005' is contained in
the display register.
X'C2'—Restore Area Station
• Function— Causes a 2790 Restore command to be issued
to designated area station, causing it to go on-line. The
response is printed on the 2740 (if present) prior to
being sent to the CPU.
• Request Format
System/360-Standard format with dj containing the
area station address.
46
CE Panel— Standard format with area station address
entered in positions 8-15 of the Data/Address switches.
8
• Response Format
System/360 request:
a. Positive— Standard response with r
b. Negative— Standard response is sent (^ and r^ =
CE panel request:
a. Positive— Standard response.
b. Negative— Catalog Number X'0006' is contained in
X'C3'-Bypass^Segment
• Function— Causes the designated segment to be bypassed.
The steps in accomplishing this are:
a. If the 2790 input is active, the actions of the 'stop
b. The designated segment is bypassed, and the loop is
c. An X'C3' response is sent to System/360 uncondi­
• Request Format
System/360 and Panel— Standard format with d^ = des­
ignated segment in EBCDIC.
and r^ containing
2
• Response Format
See "General Responses."
General Responses
System/360 Responses. The X'C3', X'C4', and X'C7'
control requests (which alter the 2790 system) share a
common System/360 response message format. These mes­
sages are also formatted for output to the 2740 and there­
fore contain line control characters.
In general, the response message will have data for both
positive and negative responses (refer to Figure 28):
r
1
r
2
r^
the EBCDIC format of the binary area station address.
EBCDIC format of the binary AS area station address)
when the designated area station fails to restore.
the display register.
2790 input' (X'C ') are performed (record stop,
6
timeout, and error encoding of incomplete transac­
tions). No X'C ' response is generated.
6
returned to its original state.
tionally (unless an invalid panel request).
= transaction control byte (standard).
= designated segment if required, otherwise
a blank (X'40').
=a. Positive— a blank character (X'40').
b. Negative— summary error byte:
X'F0'— The 2790 system was already in
and r^ containing
2