Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!gem.mps.ohio-state.edu!apple!agate!shelby!portia!roadman 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 walkerDistribution: 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