Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ucbvax!decwrl!labrea!rutgers!ucla-cs!wales
From: wales@valeria.cs.ucla.edu (Rich Wales)
Newsgroups: comp.sys.ibm.pc
Subject: Re: PC/XT 286-based accelerator opinions wanted
Message-ID: <14455@shemp.CS.UCLA.EDU>
Date: 15 Jul 88 22:31:47 GMT
References: <14382@shemp.CS.UCLA.EDU>
Sender: news@CS.UCLA.EDU
Reply-To: wales@CS.UCLA.EDU (Rich Wales)
Organization: UCLA CS Department, Los Angeles
Lines: 46

In article <14382@shemp.CS.UCLA.EDU> I wrote the following:

	I am thinking about buying a 286-based accelerator
	board for my Taiwanese turbo.

	My system has an 8-MHz NEC V-20 CPU.  The clock speed
	is software-switchable to either 4.77 or 8 MHz.  The
	RAM chips are 150-nsec.

	The accelerator I am currently thinking of is the
	"Orchid Tiny Turbo 286" -- a half-sized card unit with
	room to add an 80287 coprocessor.

I just got off the phone with a technical support person from Orchid.
She says -- very emphatically -- that the Orchid Tiny Turbo 286 *ABSO-
LUTELY WILL NOT WORK AT ALL* on a dual-speed NEC V-20 system.  It
*MUST*, she says, be an 8088-based system running at 4.77 MHz *ONLY*.

I was unable to get any intelligible explanation as to just why the
Orchid Tiny Turbo 286 wouldn't work in my system.  I asked, what if I
kept the clock speed at 4.77 MHz all the time -- and the Orchid person
said that wouldn't matter, their card still wouldn't work for me.

She said that Orchid has another product -- the Twin Turbo 12 -- that
does work OK in a dual-speed V-20 system.

I also talked with a technical support person from AST Research, about
their Hot Shot/286 accelerator card.  Same story -- AST says their Hot
Shot/286 *WILL NOT WORK* on a V-20 system; *ONLY* on an 8088 system.
And again, no intelligible reason given; just that it won't work.

I suppose my only feasible upgrade route may turn out to be to get an
AT clone motherboard (something I'm not sure I'm prepared to do right
now; and please don't flood me with "why not?"s).  But let me ask again:

Has anyone out there had any first-hand experience with 286-based
accelerator boards for PC/XT systems?

Can anyone offer a sensible explanation as to why an accelerator board
built for the 8088 would not work on a dual-speed NEC V-20 system --
even assuming that the clock was *always* run at 4.77 MHz whenever the
accelerator board was being used?

-- Rich Wales // UCLA Computer Science Department // +1 (213) 825-5683
   3531 Boelter Hall // Los Angeles, California 90024-1596 // USA
   wales@CS.UCLA.EDU      ...!(uunet,ucbvax,rutgers)!cs.ucla.edu!wales
   "We would all become unpeople, undoing unthings untogether."