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Xref: sserve comp.os.386bsd.questions:17526 comp.unix.bsd.freebsd.misc:1195 Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!simtel!news.sprintlink.net!gatech!darwin.sura.net!jeeves.niehs.nih.gov!epr0 From: duling@niehs.nih.gov (Dave Duling) Newsgroups: comp.os.386bsd.questions,comp.unix.bsd.freebsd.misc Subject: Re: External cache prevents booting? (was: FreeBSD 2.0 Boot Floppy Date: Wed, 17 May 95 13:01:12 GMT Organization: ISN Lines: 27 Message-ID: <3pcsf8$toq@jeeves.niehs.nih.gov> References: <3lvemo$eu8@kiwi.cssc-syd.tansu.com.au> <3n6f4p$4rr@klaava.helsinki.fi> <3o3ijd$3p6@park.uvsc.edu> <3o4l27$arn@nntp1.u.washington.edu> <3o8fj1$aas@helena.MT.net> NNTP-Posting-Host: epr0.niehs.nih.gov X-Newsreader: News Xpress Version 1.0 Beta #3 In article <3o8fj1$aas@helena.MT.net>, nate@trout.sri.MT.net (Nate Williams) wrote: >In article <3o4l27$arn@nntp1.u.washington.edu>, >Tim Smith <tzs@u.washington.edu> wrote: >>Terry Lambert <terry@cs.weber.edu> wrote: >>>Windows/DOS never have to handle it anyway -- they always use PIO >>>or other non-bus-mastering DMA to transfer their data from the >>>disk; if this weren't true, it would already be fixed because DOS >> >>This will come as a great surprise to all those people using NCR 53c7x0 >>or 53c8x0 SCSI chips with DOS and/or Windows, which happily do bus-master >>DMA. > >That's a big suprise to me considering that the 53cx7XX series of chips >don't do bus-mastering. And, I'm *positive* that the NCR 53cx810 >controller I installed wasn't doing bus-mastering even though it worked >under DOS. The reason I know is because it wouldn't work correctly >under OS/2 and FreeBSD because of a buggy BIOS which caused it to never >responds to interrupts. > >However, it was pretty darn fast considering it was running in PIO mode. >The author of the FreeBSD driver showed me a way to run the card in PIO mode >under FreeBSD, and I was getting 2.4MB/sec out of the drive. > Hey, no fair. Could you pass this information on to the rest of us.