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From: tankus@hsi.UUCP (Ed Tankus)
Newsgroups: comp.sys.ibm.pc
Subject: Re: 386 in IBM AT?
Message-ID: <661@hsi.UUCP>
Date: Fri, 7-Aug-87 09:52:45 EDT
Article-I.D.: hsi.661
Posted: Fri Aug  7 09:52:45 1987
Date-Received: Sun, 9-Aug-87 04:46:29 EDT
References: <1272@killer.UUCP> <503@wolf.UUCP> <407@parcvax.Xerox.COM>
Organization: Health Systems Intl., New Haven, CT
Lines: 86
Keywords: 386, 20mMHz
Summary: Cheetah Adaptor Board (A bit long winded, sorry!)

In article <407@parcvax.Xerox.COM>, burton@parcvax.Xerox.COM (Philip M. Burton) writes:
> In article <503@wolf.UUCP> enped@wolf.UUCP (Eric Pederson) writes:
> >
> >Most of the speed ratings put 386 machines with the same bus and the same
> >clock speed slightly above the compared 286 machines.  The added speed
> >isn't neccesarily worth the extra cost in getting the 386 add-on.  You'd
> >want it most likely for the ability to run multiple copies of DOS, a nice
> >linear UNIX, etc. etc.  You can speed up your AT machine with a faster
> >disk and a decent cache program.
> 
> I agree.  My preference for a new term solution would be to replce  the 286
> with a 386, and leave everything else alone.  EGA, AST multifunction card,
> disk controller, etc.
> 
> Has anyone actually installed the Cheetah upgrade?
> 
		.
		.
		.
> 
> -- 
> Philip Burton
> Xerox Corporation    408 737 4635
>  ... usual disclaimers apply ...

A friend of mine has the Cheetah Adaptor Board installed in his true blue
m/n 339 AT.  Initial installation caused a speed DECREASE.  This is because
Cheetah inserts an extra wait state in the board to compensate for the 386's
32-bit access vs the 286's 16-bit access.  The board comes with a crystal
and an adaptor for your 287.  Your 287 must be removed and placed in this
adaptor in order to be used.  He had no problems with standard software
packages such as word processors, etc.

Caveats:

My friend's applications are special.  He is a statistician and researcher
and thus requires additional features not available in a standard box.
He has added the following features in addition to the Cheetah board:

Ariel XCELX speed injector to increase overall system speed to at least
10Mhz.

Microway 287Turbo board (JUST fits in Cheetah adaptor) to increase 287
clock speed to 12Mhz.

Orchid Eccell board fully loaded with 100ns RAM.

Motherboard RAM replaced with 100ns chips.

PC-MOS/386 single user (soon to be 5 or 25 user).


He has measured the system speed once (using the Ariel utilites that come 
with the XCELX product) to be 9.5 MHz.  He has since claimed to go a bit
beyond this but has not quantified those results.

Under PC-MOS, he has generally found most DOS products to be completely
compatible.  He has trouble only with the following:

Freelance - did not work at all.  Drivers are supposed to be available
	    shortly.

Systat - a statistics package.  Systat files install with a ".sys" extension.
	 PC-MOS thinks these files are device drivers, not program files.
	 He has to talk to the software developer about this one!

Bernoulli Box - 10+10 does not install.  It requires AT LEAST the 4.11
	        driver from Iomega.  Beats me what he's got, but it's
		obviously not the latest and greatest.

Generally, terminate-and-stay-resident (TSR) packages may have a problem,
though Sidekick worked correctly.  It may have to do more with where they
are loaded in memory (PC-MOS) and when, I'm just not sure.

Sorry for being so looooooooooooong winded.

Hope this adds something to the discussion.


Cheers!

-- Ed.
    
Net  :  {noao!ihnp4!yale!}!hsi!tankus
Snail:  Health Systems Int'l, 100 Broadway, New Haven, CT 06511
Bell :  (203) 562-2101