Jumper Configurations
Table A-1
Jumper Descriptions (continued).
JUMPER #
DESCRIPTION
W4(A,B)
Installing W4A ties the STD bus pin
INTRQ1* (previously RESERVED) to the
interrupt request 1 (IR1) on the interrupt
controller, as opposed to installing W4B,
which ties the frontplane interrupt request 1
(FP1*) to IR1. Factory default installs W4A
for STD DOS and STD ROM systems.
W4A
W4B
Function
IN †
OUT
INTRQ1* (previously RESERVED)
STD bus signal drives IR1
OUT
IN
FP1* frontplane signal drives IR1
W5(A,B)
Install W5A when using the 8087 plug-in
module (zSBC 337) to bring the 8087 inter-
rupt request to interrupt request 0 (IR0) on
the interrupt controller. Install W5B for STD
DOS systems to bring the output of timer 0
to IR0 on the interrupt controller. Factory
default installs W5B.
W5A
W5B
Function
IN
OUT
8087 interrupt request drives IR0
OUT
IN †
Timer 0 output drives IR0
A-5
