Path: utzoo!attcan!uunet!snorkelwacker!usc!ucsd!helios.ee.lbl.gov!nosc!crash!pnet01!jca
From: jca@pnet01.cts.com (John C. Archambeau)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Speed of coprocessor vs. speed of main processor
Message-ID: <3090@crash.cts.com>
Date: 10 Jun 90 20:56:02 GMT
Sender: root@crash.cts.com
Organization: People-Net [pnet01], El Cajon CA
Lines: 25
X-Local-Date: 10 Jun 90 13:56:02 PDT

aceverj@accucx.cc.ruu.nl (Jaap Verhage) writes:
>In article <3076@crash.cts.com> jca@pnet01.cts.com (John C. Archambeau) writes:
>(among many other things):
>>On a a 286, it's the clock crystal divided by 2 to get the clock speed of the
>>CPU.  On the math coprocessor, it's the crystal divided by three or four.
>I've often wondered about this: the speed of the math
>coprocessor may be lower than that of the main processor?
>E.g., if I've got a 12MHz 80286, I can use a 10MHz 80287 with
>it, or something? Would a knowledgeable soul please email me
>with an explanation/clarification? I'll summarize for the
>newsgroup.

Note that this ONLY applies to the 286 to my knowledge.  On the 386(SX) the
clock speeds must be the same.
 
     // JCA

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