Path: utzoo!utgpu!watmath!att!tut.cis.ohio-state.edu!cs.utexas.edu!ut-emx!allred From: allred@ut-emx.UUCP (Kevin L. Allred) Newsgroups: comp.sys.ibm.pc Subject: Re: Mylex Motherboards - Why not? Summary: I have a mylex 386sx -- Some BIOS shadowing conflicts Message-ID: <17144@ut-emx.UUCP> Date: 15 Aug 89 21:56:50 GMT References: <4843@bgsuvax.UUCP> Organization: UT-Austin, Dept. of Chem. Engr Lines: 63 In article <4843@bgsuvax.UUCP>, bear@bgsuvax.UUCP (Michael D. Bear) writes: > > I recently took a close look at a 386sx machine based on a Mylex > motherboard. I was fairly impressed with it, compared to what I've read > on the net in the past. My question is, why would you reccommend against > a Mylex motherboard. I have read bad reccommendations in the past, but no > real reasons why. Please respond with any experiences, good or bad. > The machine I looked at, had Phoenix BIOS, Phoenix/VLSI chipset, 7 16 bit > slots, and 1 8 bit slot, and appeared to be of the highest quality. ^^ don't forget 1s and 1p too I have one of these boards running in my system now. It works almost perfectly, so far. I ran into shadow BIOS incompatibility, and it is only a minor inconvenience, since I can map any memory not used for shadowing out into the extended address space. I have a rather unusual hardware configuration, but judging by past posting the shadowing incompatibility is probably the fault of the Pheonix BIOS rather than the cards. For your info, my configuration is: Mylex MXS-16 motherboard w/ 4MB (ie. 4 1MB 100ns SIMMS) Video-7 Fastwrite VGA card w/ 256KB and Magnovox Mono VGA monitor. Seagate ST02 SCSI host addaptor and ST296N 84 MB SCSI HD. When I enable Video BIOS shadowing the ST02 can't find the HD. I tried changing the ST02 BIOS location to different places, but the problem wouldn't go away. My solution was to dissable video BIOS shadowing (System BIOS shadowing works fine); remap the RAM out into the extended memory space, and install the RAMBIOS driver shipped with the Fastwrite in my config.sys file. I wish I had a RAM installable driver for the SCSI BIOS as maybe then I could get transfers to take place fast enough to format the drive with a 1:1 interleave -- Oh well 450+ KBPS with a 2:1 interleve isn't slow, and a big RAM cache makes the actual drive speed almost unimportant. I don't know that not having the SCSI bios in RAM is what is preventing the transfers from going fast enough, but I do know that other people with 16MHz machines have claimed to be able to get the 900+ KBPS transfer rates. The system has a Norton 4.5 Si rating of 16.(5-6) at 16MHz and about 11 at 8Mhz (you figure why it is not half). I haven't had any normal DOS software that wouldn't run. I have run VMOS/3 which runs in protected mode. VMOS seems to work fairly well, but is not very robust -- It is after all a young product. I have been able to get 4 programs (the machine wasn't anywhere near out of resources so I probably could have started more) running simultaneously under VMOS -- some of them were even games. I wish I had UNIX to try out, but I'm waiting for GNU or UNIX prices to drop. I do know that Intel says their UNIX won't run on a 386sx ( you figure the company that makes the processor would know what to change :-). I don't know about the other UNIX vendors. I am happy with the Mylex board. It is a good deal for a entry level 386 board. I bought it from: MicroSource Distributors (800)-326-4276 $483 0KB shipped 2nd day UPS. PS. If anybody has any suggestions for how to solve the shadowing conflict or speed up the SCSI transfers, I would love to hear them. Buying new cards isn't the solution I want to hear :-) -- Kevin Allred allred@emx.cc.utexas.edu allred@ut-emx.UUCP