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Posting-Version: version B 2.10.2 9/18/84; site looking.UUCP
Path: utzoo!watmath!looking!brad
From: brad@looking.UUCP (Brad Templeton)
Newsgroups: net.micro.pc
Subject: Re: Interrupts and Microsoft C
Message-ID: <560@looking.UUCP>
Date: Sat, 31-May-86 15:26:02 EDT
Article-I.D.: looking.560
Posted: Sat May 31 15:26:02 1986
Date-Received: Sun, 1-Jun-86 08:53:51 EDT
References: <674@hou2f.UUCP> <2873@utcsri.UUCP>
Reply-To: brad@looking.UUCP (Brad Templeton)
Organization: Looking Glass Software Ltd. Waterloo, Ontario
Lines: 31
Summary: 

>> 
>> 	One thing that I'm doing that may be a problem is the way I
>> 	install the interrupt vector. Rather than using the get/set interrupt
>> 	vector functions in DOS I just poke the segment and offset into the
>> 	vector page at address 0x2c (IRQ3). I don't understand why this should 
>> 	cause a problem.  I did it this way with the compiled basic version.


ARRGGH.

DON'T DO THIS.   DON'T DO THIS.     DON'T DO THIS
DON'T DO THIS.   DON'T DO THIS.     DON'T DO THIS
DON'T DO THIS.   DON'T DO THIS.     DON'T DO THIS
DON'T DO THIS.   DON'T DO THIS.     DON'T DO THIS
DON'T DO THIS.   DON'T DO THIS.     DON'T DO THIS

Every time somebody does this they make another program that won't run with

a) A new 286 or 386 protected mode DOS
b) Dos emulators that run under other operating systems
c) Extended versions of DOS produced by other companies.

You may not care if your program runs, but every program like this discourages
OS writers from attempting any of the above products, and leaves the rest of
the world with the same old DOS.

When you need a function (such as fast screen i/o) that DOS doesn't provide,
you may have no choice but to bypass the OS.  But when the OS already has
a call to do the thing you want, there's rarely an excuse.
-- 
Brad Templeton, Looking Glass Software Ltd. - Waterloo, Ontario 519/884-7473