IBM 2790, Manual

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c. Invalid Response-Standard format (catalog number
X‘0001’); no message to System/360 or 2740.
X'C4'—Restore Segment
• Function-Causes the loop to stop momentarily and
the designated segment to be restored to operation. The
steps are:
a. If the 2790 input is active, the loop is brought to a
record stop. A 3-second timeout is performed.
b. The designated segment is restored.
c. An attempt is made to restore all area stations defined
in the 2715 User Tables.
d. The loop is returned to its original state and a
response message sent.
• Request Format
System/360 and CE Panel—Standard format with
dj = designated segment (EBCDIC) to be restored.
• Response Format
See “General Responses” (following “X‘C3’-Bypass
Segment”)
X'C5'—Set Read Deferred Data Mode
• Function—Causes the 2715 to read deferred data from
2715 disk storage and to send it to System/360 (see
Figure 28). The sending of the deferred data has lower
priority than priority data residing in core storage and
on 2715 disk. The resetting of this mode may be done
in two ways:
a. ‘Reset read deferred data mode’ control request.
b. The mode is automatically reset when all the follow­
ing conditions have been met:
1. The 2790 input has been stopped.
2. There is no priority or deferred data in the 2715,
either on disk or in core.
3. There is no data on the 2740 output queue.
4. There is no data on the 2790 output queue.
5. There is no data on the message-routing queue.
• Request Format
System/360—Standard format.
• Response Format
a. Positive—No response is generated as a direct result
of executing this control request. However, when the
‘read deferred data mode’ is reset automatically (see
“X‘C5’—Set Read Deferred Data Mode,” step b),
a standard positive response to the X‘C5’ control
request is generated. Note that the response indicates
that the 2715 is completely devoid of all-data.
X'C6'—Stop 2790 Input
• Function—Stops the 2790 input. The steps in bringing
the 2790 input to an orderly stop are:
a. A 2790 transactions stop (that is, no new transactions
started) is performed and a timeout is done to allow
chained transactions and message routings in progress
to complete. The duration of this timeout can be
specified as a configuration constant (0-256 seconds).
b. All incomplete transactions are flagged and all trans­
actions are assembled ready for transfer to the
System/360.
c. All deferred data in core is written on the 2715 disk.
d. An X‘C
6
’ response is sent to System/360 uncondi­
tionally (unless it was a panel request and the 2790
input was already stopped).
• Request Format
System/360 and Panel-Standard format with no
additional data required.
• Response Format
System/360—Standard format (sent to 2740 also):
a. Positive—
r j = transaction control byte
b. Negative—
rj = transaction control byte
r
2
= X‘40’ (blank)
r^ = X‘F0’ (2790 system input was already stopped)
Panel request:
a. Positive—Standard format (X‘FFC
6
’) with System/360
positive response sent to System/360 and 2740.
b. Negative—Catalog number X‘0011’ displayed (2790
system already in requested configuration). A nega­
tive panel request does not cause a System/360
response to be generated.
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