Path: utzoo!attcan!uunet!cs.utexas.edu!sun-barr!newstop!sun!amdcad!brahms!phil
From: phil@brahms.amd.com (Phil Ngai)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Info needed: AMD 80C287 chip
Message-ID: <1990Nov5.185101.19757@amd.com>
Date: 5 Nov 90 18:51:01 GMT
References: <1990Nov1.221515.15575@nntp-server.caltech.edu> <4749@trantor.harris-atd.com>
Sender: usenet@amd.com (NNTP Posting)
Organization: Advanced Micro Devices, Inc; Sunnyvale, CA
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In article <4749@trantor.harris-atd.com> sonny@trantor.harris-atd.com (Bob Davis) writes:
|These are 10 mHz chips, suitable for use with 80286 running
|12 mHz or less. (You probably will make it with 16Mhz machines).

The 287 gets a clock 2/3 of the processor. Thus, 16*2/3 = 10.67 MHz.
Now, I would never tell you to run the part past its spec, but
if you did and it worked, I wouldn't be surprised.

|Compatible with Intel 80287 (but NOT with 80287A for some reason).

I think Intel added some 387 like features to their 287A. Whether
any software USES it is another question.

|	I installed the AMD 10MHz 80C287 Math Coprocessor
|in my 12MHz 80286 machine last night. This chip, which
|AMD is currently selling for $99 (compare INTEL 80287 @ $210),
|passes INTEL's CHKCOP v. 2.00 Coprocessor diagnostic. It also
|passes MicroWay's 87TEST 8087 diagnostic. AMD's chip is touted as
|being completely compatible with the INTEL 80287.

We use the same microcode.

(I speak only for myself.)

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