Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!nrl-cmf!mailrus!tut.cis.ohio-state.edu!bloom-beacon!oberon!sdcrdcf!hplabs!hp-pcd!hpcvlx!everett
From: everett@hpcvlx.HP.COM (Everett Kaser)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Need Help w/ IRQ? ISR on HP Vectra
Message-ID: <1180012@hpcvlx.HP.COM>
Date: 12 Apr 88 16:51:08 GMT
References: <358@ga.ecn.purdue.edu>
Organization: Hewlett-Packard Co., Corvallis, OR, USA
Lines: 50

I assume (and we all know what that makes out of 'u' and 'me', huh?) that
you're taking over interrupt 9, the keyboard hardware interrupt.  I'm also
assuming that you're saving the old interrupt vector and restoring it before
you return to DOS (unless you're a terminate-stay-resident, of course).
You see, there are many questions about your situation that makes an answer
difficult.  However, here is the skeleton of an ISR that I've used that might
help.
;
int9isr:
	push	ax
	push	bx
	push	cx
	push	dx
	push	si
	push	di
	push	bp
	push	ds
	push	es

	in	al,60h			; get keyboard data byte
;
; at this point test the scan code in AL for a value that you want, or do
; whatever with it that you do.
; then,
;
	in	al,61h			; reset keyboard
	mov	ah,al
	or	al,80h
	out	61h,al
	xchg	ah,al
	out	61h,al

	mov	al,20h			; send End-Of-Interrupt command to
	out	20h,al			;    the interrupt controller

	pop	es
	pop	ds
	pop	bp
	pop	di
	pop	si
	pop	dx
	pop	cx
	pop	bx
	pop	ax
	iret
;
;
I hope that this helps.

Everett Kaser
!hplabs!hp-pcd!everett