RCA 70/46 - Page 71

Condition Code
(Cont'd)
Input/Output Operation
Start Device Instruction Condition Code Settings (Cont'd)
Condition I/O Operation
Code Initiated
2 No
3
No
Meaning
1. A selector channel is specified that is busy.
2. A selector channel is specified that has an interrupt
pending (termination or external device request).
3. The multiplexor channel is specified and it is operating
in burst mode.
4. The multiplexor channel is specified and the addressed
device control electronics is busy with addressed or
non-addressed device.
5. The multiplexor: channel is specified and the addressed
device control electronics has a termination interrupt
pending.
6. A burst mode operation is directed to the multiplexor
and there is a termination interrupt pending on one of
the attached device control electronics.
1.
A selector channel is specified that is not in the system.
2. The specified device control electronics is inoperable.
Halt Device Instruction Condition Code Settings
Condition I/O Operation
Code Initiated
o No
1
No
2
Yes
3
No
Meaning
1. The device control electronics or the device specified on
the multiplexor channel is not busy. No termination
is required.
2. A selector channel or the multiplexor channel operat-
ing in burst mode is specified and it is not busy. No
termination is required.
3. The multiplexor channel is specified and the addressed
device control electronics has a termination interrupt
pending. No termination is required.
This condition code indicates that the specified device is
on the multiplexor channel and that the standard device
byte has been stored in the channel registers for the multi-
plexor channel. The channel status byte is never stored.
The standard device byte is stored under the following
conditions:
1.
The specified device indicates that a device request
interrupt pending condition is present. The external
device request interrupt pending bit in the standard
device byte is set.
2. The specified device is busy but the device control
electronics is not busy (i.e., tape rewinding). The
device busy bit in the standard device byte is set.
3. The specified device is inoperable. The device inop-
erable bit in the standard device byte is set.
1. A selector channel is specified that is busy.
2. The multiplexor channel is specified and it is operating
in the burst mode.
3. The multiplexor channel is specified and the addressed
device control electronics and device are busy.
1.
A selector channel is specified that it is not in the
system.
2. The specified device control electronics is inoperable.
62