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From: kaleb@mars.jpl.nasa.gov (Kaleb Keithley)
Newsgroups: comp.sys.ibm.pc
Subject: Re: yo mother
Message-ID: <2500@jato.Jpl.Nasa.Gov>
Date: 4 Jan 90 16:53:30 GMT
References: <20726@kuhub.cc.ukans.edu>
Sender: news@jato.Jpl.Nasa.Gov
Reply-To: kaleb@mars.UUCP (Kaleb Keithley)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Lines: 40

In article  ARRITT@kuhub.cc.ukans.edu  writes:
>I've seen some discussions in this group about replacing motherboards.
>A recent issue of "PC" magazine has ads for 286 motherboards for about
>$250 or so.  This seems like a very attractive alternative to buying
>a whole new system.
>
Why not spend $350 and get a 386SX?

>My question is: what is involved in replacing the motherboard?  That is,
>can it be done by someone who is mechanically adept, has some knowledge of
>electronics, and has done a little bit of fooling around with computer
>hardware (like installing memory chips or disk drives)?  Or, is it a job
>best left to a real computer hardware whiz (like most readers of this
>newsgroup :-)  .... ?  (Maybe the answer is "if you have to ask, then
>you can't do it"!)
>
If you can put in a disk drive, then you can probably handle a motherboard;
just be carefull, static can destroy CMOS parts on a motherboard faster than
you can take it out of its static protective bag...

>Also, how well do these things match up, physically?  Will a "typical" 
>286 motherboard fit into a "typical" XT-clone case, without a lot of 
>drilling into metal and so forth?
>
What you need is a so called Baby AT motherboard.  This will fit in your XT
case, but, things like the turbo switch, keylock, speaker, etc (if your XT
has them) will not "just plug in".  The keylock logic is reversed, i.e. locked
is unlocked.  I strongly suggest spending $50 and getting a Baby AT case as
well.  Your XT power supply will fit,  All the switch and light and lock
wiring will fit, and it is generally a cleaner installation overall.

One additional thought is power supply,  most ATs (especially with lots of ram
and hard disk) want a minimum of 200 watts.  My XT to AT conversion is doing
okay with the XT 150 watt supply, but I'm sure lots of people will tell you,
as they did me, that 150w is on the hairy edge of not working.  Consider 
spending another $60 for a 200 watt supply.
Chewey, get us outta here!
                 
kaleb@mars.jpl.nasa.gov             (818)354-8771
Kaleb Keithley