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Path: utzoo!utcsri!utai!indra
From: indra@utai.UUCP (Indra Laksono)
Newsgroups: net.micro.pc
Subject: Re: Questions on Interrupts and DOS
Message-ID: <499@utai.UUCP>
Date: Thu, 9-May-85 23:13:00 EDT
Article-I.D.: utai.499
Posted: Thu May  9 23:13:00 1985
Date-Received: Thu, 9-May-85 23:42:11 EDT
References: <1028@phs.UUCP>
Organization: CSRI, University of Toronto
Lines: 29

> 
>         The only really satisfactory solution for video intensive 
> programs is to write your own custom interrupt routine and patch it into 
> the interrupt dispatch table through Dos function call 25h.  Note that 
> even if your machine has reserved interrupt 10h for some other purpose, 
> you can pick some other (unused) interrupt.  Simply take debug, find 
> all instances of the int 10h instruction (s cs:0 f000 cd 10), and replace 
> the 10 with your new interrupt number.
> 
> 
>         Jeffrey William Gillette        ...!duke!phs!lisa
>             Duke University

The idea to write an interrupt handler is a good one, the one to use
another interrupt number is bad, there is no reason why you can't use
INT 10H.  The INT10H are all video functions anyway, so there is a very
good chance that your program will use most, if not all of them.  If you
did implement the COMPLETE INT 10H in another routine,  this patch will
work for other programs that need INT 10H as well, not just one.
It will probably help if you do :
	A>DEBUG
	-D0:40		; 10H * 4 = 40H
	0000:0040 XX YY AA BB
	-UBBAA:YYXX
	BBAA:YYXX  ; The routine in the bios
	.........
If you redirect your output to the printer, you can study it in your
leisure and optimize it yourself.  I know because I have tried something
similar on my sanyo 555 [vb].