HP Vectra Technical Reference Manual page 396

Master's IRQ
IRQ3(OBH)
IRQ4(OCH)
IRQS(ODH)
IRQ6(OEH)
IRQ7(OFH)
Interrupt Request Description
Serial Port 1
Serial Port 0
Printer Port 1
Diskette
Printer Port 0
Note: The numbers in parentheses are the interrupt vector numbers generated by the IRQs.
The following example shows how the 8259A controllers are programmed on initialization:
CLI
PROGRAM_MASTER:
MOV AL, 71H
OUT 20H,AL
JMP $+2
MOV AL,08H
OUT 27H,AL
JMP $
+2
MOV AL,06H
OUT 27H,AL
JMP $+2
MOV AL,07H
OU·T 27H,AL
JMP
$ +2
PROGRAM_HP_SLA VE:
MOV AL, 71H
OUT 7CH,AL
JMP $+2
MOV AL,68H
OUT 7DH,AL
JMP $+2
MOV AL,07H
OUT 7DH,AL
JMP $+2
MOV AL,07H
OUT 7DH,AL
JMP $+2
MOV AL,68H
OUT 7CH
JMP
$ +2
PROGRAM_STD_SLA VE:
MOV AL, 71H
,. Disable interrupts
" ICW7: Initialization Command
,. Interrupt Vector Base
at
08H
,. Define master with
two
slaves
" one
at
IRQ
7
and one
at
IRQ2
,. 8086/88 Mode
,. ICW7: Initialization Command
,. Interrupt Vector Base
at
68H
" Slave 10 number
,. 8086/88 Mode
,. Place HP slave on special
,. mask mode.
" ICW7: Initialization Command
I/O Port Map 387