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From: bomgard@iuvax.cs.indiana.edu (Tim Bomgardner)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Increasing #task switches per second (> 18.2), help
Keywords: task timer 8253-5 8254.2
Message-ID: <76399@iuvax.cs.indiana.edu>
Date: 4 Dec 90 19:59:51 GMT
References: <4348@dnlunx.pttrnl.nl> <75778@iuvax.cs.indiana.edu>
Organization: Indiana University, Bloomington
Lines: 14

In article <4348@dnlunx.pttrnl.nl> filetp@dnlunx.pttrnl.nl (Peter Filet) writes:
>I am developing an Operating System, in the Protected Mode of the i286
>processor.
> (wants a faster system clock)

This is actually very easy to do.  The idea is to hook the clock tick interrupt,keeping the original vector and substituting your own handler.  Then, if you
want, say, a 4X clock rate (72.8/sec), you call the original handler every
fourth tick.  The rest of the OS has no idea anything has changed.  Indeed,
from its point of view, nothing has.

I'll be happy to send the .asm code that does this to anyone who wants it.

Academic types can usually tell you why you can't do something.  Commercial
software developers can usually tell you how to do it anyway :) .