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From: bobb@vice.ICO.TEK.COM (Bob Beauchaine)
Newsgroups: comp.lang.pascal
Subject: Re: How to detect MS Mouse driver
Message-ID: <6432@vice.ICO.TEK.COM>
Date: 3 Dec 90 20:40:11 GMT
References: <1990Nov29.141927.243@maytag.waterloo.edu> <6405@vice.ICO.TEK.COM> <17855@hydra.gatech.EDU>
Organization: Tektronix Inc., Beaverton, Or.
Lines: 33

In article <17855@hydra.gatech.EDU> bb16@prism.gatech.EDU (Scott Bostater) writes:
>In article <6405@vice.ICO.TEK.COM> bobb@vice.ICO.TEK.COM (Bob Beauchaine) writes:
>
>First, the interrupt table at low memory is made up of double word addresses,
>hence int 0's address occupies $0000:$0000 through $0000:$0003, int 1's address
>occupies address $0000:$0004 through $0000:$0007, etc.  Int $33's address
>would be $0000:$00CC through $0000:$00CF.
>

  Yes, I get bit by that one every time and never seem to learn (or at least
  remember.).  Thank you for pointing that out.  This is the method I use, 
  BTW, so I know it is effective (with the proper correction).

>Secondly, this is a poor programming technique.  Don't rely on absolute memory
>references unless it absolutly neccessary.  In this case its better to let the 
>operating system give you the correct memory address.  Turbo pascal even has 
>this built in.
>
 
  On this point, however, I disagree wholeheartedly.  If IBM or anyone else
  moves the interrupt table, how many millions of machines are going to be
  obsolete?  Poor programming practice is largely a matter of taste, and I
  use direct memory access whenever possible. If screen drawing programs
  were limited to using the BIOS for screen I/O, video updates would still
  be in the stone age for speed.  While it may be nice that the Operating
  system provides these resources, limiting yourself to these routines 
  will never tap the full potential of your machine.

  [Off podium]


  Bob Beauchaine
  bobb@vice.ICO.TEK.COM


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