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From: roadman@portia.Stanford.EDU (arthur walker)
Newsgroups: comp.sys.amiga
Subject: Re: XT BridgeBoard Accelerator Cards ... Any success stories?
Summary: a success story w/bridge acceleration
Message-ID: <5490@portia.Stanford.EDU>
Date: 3 Oct 89 17:42:28 GMT
References: <4242@cbnewsh.ATT.COM> <2105@cbnewsl.ATT.COM>
Sender: arthur walker 
Distribution: usa
Organization: Stanford University
Lines: 32

In article <2105@cbnewsl.ATT.COM>, mgh1@cbnewsl.ATT.COM (matthew.g.hetman) writes:
> In article <4242@cbnewsh.ATT.COM>, doug@cbnewsh.ATT.COM (douglas.sulpy) writes:
> > Has anyone successfully used an Accelerator card with an XT BridgeBoard?
> 
> I tried two accelerator cards with my XT bridgeboard. One was a glaring
> success which led me to a disasterous failure. I first tried the SOTA-386X
> accelerator card and it worked great. I measured  6 fold improvement in

I have had success with the Orchid PC Turbo286e.  Note this is NOT a half
card with cache ram and socket for the 8088 and a ribbon connector to its
original socket.  It is a full card with a megabyte of 16 bit memory, one 
segment of which at a time can be mapped to the 20 bit address space on
the PC bus.  The board is fired up after a normal boot by loading a device
driver and running a transfer-control program, which boots the 286 board
with many interrupts hooked, with a ram copy of the rom bios in the top segment
of the 16 bit memory; this program on the 8088 then services the i/o from
the 286 with the native bios, which in this case means through the amiga.
The screen buffer in 16 bit memory is periodically swapped, etc.

one can switch back to 8088 mode at any time.  While in turbo mode any 
undedicated 8088 memory can be used as a disk cache.  

Anyway, the list price on this board is horribly expensive but I've seen
three of them used in the bay area in the last 4 months for $150-250. 

Norton SI 3.0 is 9.2.  I have found with janus 2.0 that Aread and Awrite
do not work from turbo mode; however, since the included software allows
devices loaded in 8088 mode to be used from the 286, jlinked partitions
as well as the makeAB boot disk are accessible.  

Art walker
walker@meggie.stanford.edu