Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!hellgate.utah.edu!uplherc!wicat!jimi!rob
From: rob@jimi.UUCP (SYS$REALNAME)
Newsgroups: comp.os.msdos.programmer
Subject: Re: TSR PROGRAMMING PROBLEMS
Message-ID: <00069@jimi.UUCP>
Date: 5 Feb 91 23:36:11 GMT
References: <688@tronsbox.xei.com> <234@nazgul.UUCP> <1991Jan21.233029.29058@murdoch.acc.Virginia.EDU> <1891@kuling.UUCP> <1991Jan30.002515.13780@msuinfo.cl.msu.edu> <8266@ucdavis.ucdavis.edu>
Reply-To: rob@jimi.UUCP
Organization: WICAT Systems Inc., Orem Utah
Lines: 21

In article <8266@ucdavis.ucdavis.edu>, chiang@iris.ucdavis.edu (Tom Chiang) writes:
> [some code deleted]

>kidone:
>	push dx ----- 
>	push ax     | 
>	mov dl,'z'  |
>	mov ah,5H   | ----- these are the instructions i added
>	int 21H     |
>	pop ax      |
>	pop dx ------
>	iret
>new_keyboard_io		endp
>

 The only DOS functions that are safe to call in this ISR are 0h-0Ch. The
 Waite Group's 'MS-DOS Bible' has an excellent example and explanation
 of TSR's.
 
   Rob Carlson