[net.micro] Changing IBM PC clock crystals

ins_aeas@jhunix.UUCP (Earle A .Sugar) (03/09/86)

I have heard that it is possible to speed up an IBM PC by replacing the
stock clock crystal with a faster one.  Has anybody actually done this?
I wouldn't doubt that IBM designed the PC to run at a higher clock 
speed and released it with a lower one to increase quality  control.
If anybody has done this, how are various drivers (particularly 
the disk drive driver) that use software timing loops affected?
Of course, if I really wanted a major project, I could have clock
speed cut in half when the disk drive is being active, but I doubt
that my boss would appreciate her PC being bastardized like that.
She is looking for a cheap way to speed up her PC, which is extremely
slow for the heavy database work she does.  Because of university politics,
she has not been able to get an AT or a faster compatible.  
     If it is not feasible to just swap crystals, does anybody know of
a cheap speedup board that is reasonably priced (most seem to be 
in the >$500 range).  8087 support is not necessary.

adthanksvance

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Earle A. Sugar
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cramer@kontron.UUCP (Clayton Cramer) (03/20/86)

> I have heard that it is possible to speed up an IBM PC by replacing the
> stock clock crystal with a faster one.  Has anybody actually done this?
> I wouldn't doubt that IBM designed the PC to run at a higher clock 
> speed and released it with a lower one to increase quality  control.
> If anybody has done this, how are various drivers (particularly 
> the disk drive driver) that use software timing loops affected?
> Of course, if I really wanted a major project, I could have clock
> speed cut in half when the disk drive is being active, but I doubt
> that my boss would appreciate her PC being bastardized like that.
> She is looking for a cheap way to speed up her PC, which is extremely
> slow for the heavy database work she does.  Because of university politics,
> she has not been able to get an AT or a faster compatible.  
>      If it is not feasible to just swap crystals, does anybody know of
> a cheap speedup board that is reasonably priced (most seem to be 
> in the >$500 range).  8087 support is not necessary.
> 
> Earle A. Sugar

Funny you should ask.  I just bought a speedup kit from MicroSpeed called
Fast88.  It works for me in my antique PC at 6.1 Mhz, and the technical
support guy says that my DMA controller chip is flaky, which is what is
preventing it from running at 6.7 Mhz.  I will be posting a full review
of this product in the next couple of days, as soon as I determine if
the DMA controller chip replacement solves my problem.