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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!nntp.coast.net!sgigate.sgi.com!swrinde!cs.utexas.edu!howland.reston.ans.net!newsfeed.internetmci.com!news1.erols.com!newsmaster@erols.com From: Ken Bigelow <kbigelow@www.play-hookey.com> Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Can FreeBSD 2.1.1 support Cyrix 6x86??Etc... Date: Thu, 27 Jun 1996 20:29:51 -0700 Organization: Erols Internet Services Lines: 47 Message-ID: <31D351AF.7AE7@www.play-hookey.com> References: <Dt5v2D.A6I@news2.new-york.net> <4qjgpi$4ds@uriah.heep.sax.de> <4qnbps$60e@hole.sdsu.edu> NNTP-Posting-Host: kenjb05.play-hookey.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 2.02 (Win16; I) Larry Riedel wrote: > > J Wunsch (j@uriah.heep.sax.de) wrote: > > le@put.com (Louis Epstein) wrote: > > > > > Just what is the pre-release status of 2.1.1 at the moment? > > > Another posting indicated that a 6x86 option was only added to the > > > > Hmm, i seem to remember that the 6x86 works fine, but is detected as a > > 486. (So if you accidentally removed the I486_CPU, it won't work for > > you.) > > I have a 120MHz 6x86 on an ASUS T2P4 motherboard, and FreeBSD > 2.1-RELEASE faithfully crashes after a few minutes with the > internal cache enabled. If I turn the internal cache off with > the BIOS, it works like a champ (albeit a slow champ). I don't > know if it is the interaction of the CPU and the motherboard or > if it has something to do with FreeBSD. I guess I will try it > with a more robust OS like Windows 95. ;) > I have similar problems with cachre memory in a number of circumstances, but I think I know why. As near as I can guess, slower cache RAMs (20 ns) aren't keeping up with the demand put on them by FreeBSD. In running a 486DX-50 on an ALI-1429G motherboard with 20 ns cache (size doesn't matter, I've tried 128K and 256K), the Phoenix BIOS defaults to fast cache mode. DOS seems to be happy with that, but even installing FreeBSD from a DOS partition causes problems -- the Alt-F2 screen reports a lot of junk dropped from the bin.xx files. As near as I can guess, the motherboard thinks the cache is keeping up and reports all is well, but FreeBSD is trying to read from the cache before it is fully settled, with unpleasant results. I've had a few unexplained crashes with DOS 6 and Windoze 3.1 as well, and this could be related. Anyway, there are two solutions other than shutting down your cache: either slow down the cache access, or else use faster cache RAMs. I use the former technique on the ALI motherboards because I already have the RAMs and slow cache is better than none. The faster cache RAMs work fine on a board running an AMD 5x86-133 at full tilt, so that's the optimal solution. PS: Go ahead and run Win95 if you're really a glutton for punishment -- I have to have one such machine at work to test software and generate screen prints. The very kindest comment I can make is that you will *never* find Win95 on any of my own machines, and I'm running a 32-node subnet. Ken