A. Jumper Configurations
113
W17-22
Maskable Interrupts - assigns up to nine interrupt sources to the interrupt controller
inputs. Each interrupt input has two possible sources selected by installing a jumper in
position "a" or position "b." Other combinations are possible with wire wrap techniques.
Interrupt inputs not used in the application must be masked in software.
Jumper Installed Interrupt Source
Interrupt
†
W17a
STD bus INTRQ4* IR5
W17b
J2 pin 6
IR5
†
W18a
STD bus INTRQ2* IR6
W18b
J2 pin 8
IR6
†
W19a
Printer
IR7
W19b
J2 pin 10
IR7
W20a
Parallel I/O
IR8
†
W20b
Real Time Clock
IR8
W21a
Serial COM4
IR9
†
W21b
STD bus INTRQ*
IR9
†
W22a
Serial COM3
IR13
W22b
Math Coprocessor IR13
W23
When W26B is installed:
•
W23A is reserved.
•
W23B connects the 1284 port DMA request to the 386 EX DRQ1.
†
Factory default configuration for DOS systems.