[comp.sys.ibm.pc.hardware] Upgrading 386SX 20MHz --> 25MHz

mcphail@dataco.UUCP (Alex McPhail) (01/24/91)

I have read some quite informed discussions about upgrading
a 16MHz 386SZ to 20MHz.  I have followed it carefully, because
I have a 20MHz 386SX.  All the parts are stamped 20MHz; so this
is the real McCoy.

My question is:  Can I upgrade this to 25MHz by simply replacing
the crystals?

Thanks in advance for your help

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  Alex

mlord@bwdls58.bnr.ca (Mark Lord) (01/25/91)

In article <323@dcsun21.dataco.UUCP> mcphail@dataco.UUCP (Alex McPhail) writes:
<
<I have read some quite informed discussions about upgrading
<a 16MHz 386SZ to 20MHz.  I have followed it carefully, because
<I have a 20MHz 386SX.  All the parts are stamped 20MHz; so this
<is the real McCoy.
<
<My question is:  Can I upgrade this to 25MHz by simply replacing
<the crystals?

I would give this VERY GOOD odds of success.  Try it!

Intel does not currently sample 386sx's for 25Mhz operation because 
they do not want them to compete with the more profitable 386dx's.

Thus, I suspect that a large number of 20Mhz SX's will work just fine
at 25Mhz.

So get yourself a 50Mhz crystal oscillator and try it.  If it does not work,
then put the old one back in the socket.  Or try again for 23Mhz instead
using a 46Mhz oscillator.

(disclaimer:  I have only done the 16Mhz -> 20Mhz conversion- no problems).

-- 
 ___Mark S. Lord__________________________________________
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