Return to BSD News archive
Newsgroups: comp.unix.bsd Path: sserve!manuel.anu.edu.au!munnari.oz.au!uunet!retix.com!eab!erik From: erik@eab.retix.com (Erik Forsberg) Subject: Re: The ultimate 386BSD machine? (FAQ fodder) Keywords: 386BSD References: <1992Oct8.072512.8700@elroy.jpl.nasa.gov> <Bvsss4.9nz@ibmpcug.co.uk> Organization: Retix, Santa Monica CA Date: Thu, 8 Oct 1992 16:49:19 GMT Message-ID: <1992Oct8.164919.14096@eab.retix.com> Lines: 45 In article <Bvsss4.9nz@ibmpcug.co.uk> adrian@ibmpcug.co.uk (Superuser) writes: >In article <1992Oct8.072512.8700@elroy.jpl.nasa.gov> earle@elroy.jpl.nasa.gov (Greg Earle - Gainfully Unemployed) writes: >>- I have seen some benchmarks whereby a 486DX2/66 outperforms a 486DX/50. But >> I saw a posting by Barry Shein that indicated that due to the bus speed on >> the former being only 33 MHz, this would not be a good idea as doing things >> like bitblts in X would be faster on a "native" 50 MHz system. This seemed >> perfectly reasonable, so it seems that a 486DX/50 is the best idea. Right? >> > >I have run 386BSD on both, albeit without X (I cant get the card and >monitor with the correct resolution at the same time in the office). >To be quite honest, there is not much difference between the two. I >think in terms of 386BSD, when you get to these speeds, either will >do. *I* would go for the DX50, since that has the faster bus system. >and generally, disk speed has been my downfall. > >>- I saw a posting from Lynne Jolitz that I believe mentioned that a 32-bit >> disk controller was the best idea. I have assumed from subsequent postings >> that the Adaptec 1542B is the "controller of choice", no? OK, but that's >> an EISA board, correct? But now I'm confused, I thought that 386BSD didn't >> support "EISA machines". What's the deal? >> >> As an adjunct to this, I expect Julian to jump in with "But an Adaptec 1742A >> is supported with my new SCSI subsystem ... ". Fine, but can one get the >> system up first (with it installed) to get to the point where one can >> recompile the kernel with the new SCSI subsystem? >> > >Julians SCSI system works by setting th 1742B into 1542 mode, and then >when the probe works out its a 1742, it shoves the card into enhanced >mode itself. > This seems to be a BAD approach. It would EXCLUDE all existing 1740 cards from functioning. ONLY the newer 1740A (and obviously 1742A) allows switching between standard and enhanced mode at runtime. The older 1740 (which probably still is the most common Adaptec EISA card out there) requires you to download firmware that is specific to the operating mode. So, useful support for Adaptec 1740 cards, requires support for enhanced mode in everything (boot blocks, standalone boots and kernels). -- --------------------------------------------------------------------------- Erik Forsberg, erik@eab.retix.com Phone: (310) 476-7133 FAX: (310) 476-7657