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From: waldref@psueea.UUCP (Greg Waldref)
Newsgroups: net.micro.pc
Subject: Re: Re: 80287 and the IBM AT
Message-ID: <253@psueea.UUCP>
Date: Thu, 4-Sep-86 01:55:36 EDT
Article-I.D.: psueea.253
Posted: Thu Sep  4 01:55:36 1986
Date-Received: Fri, 5-Sep-86 05:06:45 EDT
References: <3312@utcsri.UUCP>
Reply-To: waldref@psueea.UUCP (Greg Waldref)
Distribution: net
Organization: Dept. of Electrical Engineering, Portland State University; Portland OR
Lines: 24

In article <3312@utcsri.UUCP> henderso@utcsri.UUCP (Mark Henderson) writes:
>I heard recently that the 80287 runs at a clock speed of only 5.3 MHz when
>in an IBM AT and also that one can purchase a small board which fits into the
>80287 socket on the AT, to drive it at 8 MHz (assuming of course one has an
>80287-8). Where can one purchase such a board? Any information would be
>appreciated. If you have them, please include prices.

Depending on what you are using, putting a 287 may not get you
anywhere.  In fact, it may slow down your system!  
 
You may want to check the IBM special issue (10/85) of Byte, page 66 on.
the benchmarks that they ran did not give the increase in proformence
that you might expect.  In at least one case it slowed it down.

They used different clocks for both the 286 and 287;
286: 6 & 9 MHz
287: 0, 4, & 8 MHz
 
You might check byte for the speed up board for the 287, as I have seen
them in byte.

greg waldref

....tektronix!psu-cs!psueea!waldref