IBM 6151 Maintenance And Service Manual page 614

Jumper Settings
Set the jumpers to select Primary or Alternate addresses.
Set the jumper to select Interrupt Level 3 or Interrupt Level 9.
9-063-2 Service Manual
Interrupt
Level 3
0'
Inlerrupl
Level 9
~
P,lma,y
~
0'
~
Seconda,y
r\,JZB1Il9