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Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!bunyip.cc.uq.oz.au!munnari.oz.au!spool.mu.edu!howland.reston.ans.net!gatech!news.byu.edu!cwis.isu.edu!u.cc.utah.edu!cs.weber.edu!terry From: terry@cs.weber.edu (Terry Lambert) Newsgroups: comp.os.386bsd.bugs Subject: Re: FreeBSD, fd0d: hard error Date: 9 Sep 1994 04:54:15 GMT Organization: Weber State University, Ogden, UT Lines: 36 Message-ID: <34oppn$3rb@u.cc.utah.edu> References: <3486q6$dr6@pdq.coe.montana.edu> <34a91e$h2f@sol.sun.csd.unb.ca> <34iv96$ik4@pdq.coe.montana.edu> NNTP-Posting-Host: cs.weber.edu In article <34iv96$ik4@pdq.coe.montana.edu> nate@bsd.coe.montana.edu (Nate Williams) writes: ] Do these other OS's reside on the same hardware? People have written ] floppies with one set of hardware that will not work, and then taken ] the exact same media and written with a different computer and it ] worked fine. Actually, this is generally a problem only if the timing comes off the bus instead of from a clock crystal, and then generally result in a floppy created in "turbo mode" not reading in "non-turbo mode" and vice versa. We have a couple of GEM machines with cruddy controllers here with exactly that problem. But as to the original problem, it "feels" like a seek-past-end-of-track attempt, despite bit 3 saying it's a CRC error. I see this crap all the time after booting because the head is in the wrong position when a read request is made, and it ends up being a relative head position that would be OK if the head were really at 0. Seeking the head on Initializing the device and keeping running track of where it's supposedly at (shades of a Calcomp plotter driver here) and operating on the basis of relative deltas has cleared the problem for me. Oh, you'll also see it (or similar) on some hardware if you are using the wrong device (block vs. character) and aren't reading for exact sizes, unless you modify the buffering code at the same time you do the above. The block and character devices suprised me the first time -- then again, I'm used to SCO for floppy crap. Terry Lambert terry@cs.weber.edu --- Any opinions in this posting are my own and not those of my present or previous employers.