Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!ccu.umanitoba.ca!umcarls9
From: umcarls9@ccu.umanitoba.ca (Charles Carlson)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: can you replace a 16mhz 386sx with a 20mhz 386sx?
Message-ID: <1991Apr5.001636.7817@ccu.umanitoba.ca>
Date: 5 Apr 91 00:16:36 GMT
References: <1991Apr4.043028.9227@hub.cs.jmu.edu> <1991Apr4.164920.5203@wdl1.wdl.loral.com>
Distribution: comp
Organization: University of Manitoba, Winnipeg, Canada
Lines: 24

In <1991Apr4.164920.5203@wdl1.wdl.loral.com> engle@wdl1.wdl.loral.com (David Engle) writes:

>In article <1991Apr4.043028.9227@hub.cs.jmu.edu> jmidili@hub.cs.jmu.edu (jeff midili) writes:
>>I was wondering if it is possible to replace a 16mhz 386sx with
>>a 20mhz chip.  Has anyone done this?  Do the BIOS need to be 
>>replaced too?  Are any companies offering a trade in value for
>>the old chip for a new one???

Of course you could, if you had the eyesight of an owl and the agility
of a cat.  You're looking at desoldering/soldering ~100 pins less than a 
millimeter apart.  I've never seen any socketed SX chips, just surface 
mount.
No BIOS changes are necessary.  Only IBM had the nerve to govern a BIOS.

>You may find that your 386SX mother board has a jumper selection option
>for the clock speed.  The first 386SX-16 I owned had one of these, I just
>moved the jumper and the system ran just fine.  The memory chips in the
>system were already of a fast enough speed to handle the new clock rate.

Same with mine, but I also had to add a 40Mhz oscillator.  
All my chips are stamped 16Mhz, but I've been running the system at 20
for several weeks now, 24hrs a day, without a single problem.
None of the C&T chips are even warm to the touch, and the SX chip
itself is only slightly warm.