IBM RT PC Options Installation page 155

• IBM Monochrome Display and Printer Adapter not used
– The first adapter jumper modules should be set to the
primary (Interrupt Level 4 for the serial jumper and
Interrupt Level 7 for the parallel jumper) position.
– The second adapter jumper modules should be set to the
alternate positions (Interrupt Level 3 for the serial jumper
and Interrupt Level 5 for the parallel jumper).
• IBM Monochrome Display and Printer Adapter used
– With one IBM Personal Computer AT Serial/Parallel Adapter:
Set the jumper modules to the alternate position (Interrupt
Level 3 for the serial jumper and Interrupt Level 5 for the
parallel jumper).
– With two IBM Personal Computer AT Serial/Parallel
Adapters:
The first adapter jumper modules should be set to the
alternate positions (Interrupt Level 3 for the serial jumper
and Interrupt Level 5 for the parallel jumper).
The second adapter jumper modules should be set to the
primary position (Interrupt Level 4 for the serial jumper and
Interrupt Level 7 for the parallel jumper).
Note: The parallel port of the second serial/parallel adapter
is not used in this case. Ensure that the parallel port of
the second adapter is not activated by the AIX DEVICES
command, or a conflict will exist on Interrupt Level 7.
Section 6. Communication and Network Adapter Options 6-7