IBM System/360

(Ch)
Drop
Select Out
(Ch)
Raise
Command Out
Yes
Wait
No
assumes proper operation
of hold out as well. Thus,
select out up means select
out and hold out up, and
select out down means
either select out or hold
The channel processes
the status byte
for device
end
unit exception,
attention or status
modifier. This ends
the sequence
No
This must be a
stacked status
byte
All mention of select out assumes proper operation
of hold out as well. Thus, select out up means
select out and hold out up, and select out down
means either select out or hold out down
\
The byte on bus in need not be
valid after the rise of the out tag.
The channel cannot accept the data or status.
Stop or stack is therefore indicated
, IBM CONFIDENTIAL
S/360 123