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From: phil@amdcad.UUCP (Phil Ngai)
Newsgroups: net.micro.pc
Subject: Re: Re: PC/AT fast xtal warning
Message-ID: <8532@amdcad.UUCP>
Date: Tue, 21-Jan-86 02:53:30 EST
Article-I.D.: amdcad.8532
Posted: Tue Jan 21 02:53:30 1986
Date-Received: Wed, 22-Jan-86 04:57:20 EST
References: <604@harvard.UUCP> <283@omen.UUCP> <187@intelca.UUCP>
Reply-To: phil@amdcad.UUCP (Phil Ngai)
Organization: AMD, Sunnyvale, California
Lines: 18

In article <187@intelca.UUCP> glen@intelca.UUCP (Glen Shires) writes:
> The 286 clock rate is half the crystal, so a 20MHz crystal uses a 10MHz 286.
> 286's are rated at 6, 8, 10, 12.5 MHz.

There's also a chip in the 286 family called the 82284 which is the
actual oscillator device. It too comes in speeds and is therefore
another possible reason why a 20 MHz crystal doesn't work in a PC/AT.

Note: I don't even know if a PC/AT uses the 82284, although I would be
surprised if it didn't, and I don't recommend changing the hardware
around if you want it to keep working.
-- 
 (C) 1986 Joe Random is not a valid copyright.
 Copyright 1986 Joe Random is.

 Phil Ngai +1 408 749 5720
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