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Newsgroups: comp.os.386bsd.questions Path: sserve!newshost.anu.edu.au!munnari.oz.au!constellation!osuunx.ucc.okstate.edu!moe.ksu.ksu.edu!zaphod.mps.ohio-state.edu!math.ohio-state.edu!wupost!bigboy.sbc.com!news.mtholyoke.edu!news.smith.edu!sophia.smith.edu!jfieber From: jfieber@sophia.smith.edu (J Fieber) Subject: Re: Elusive SCSI problems (Adaptec 1542C) <snarl!> Message-ID: <1993May13.132848.18516@sophia.smith.edu> Keywords: Adaptec 1542C, Quantum, SCSI, 386bsd Sender: root@sophia.smith.edu (Operator) Organization: Smith College References: <1993May12.023959.20121@sophia.smith.edu> <1993May12.205857.8857@fcom.cc.utah.edu> Date: Thu, 13 May 1993 13:28:48 GMT Lines: 88 In article <1993May12.205857.8857@fcom.cc.utah.edu> terry@cs.weber.edu (A Wizard of Earth C) writes: >In article <1993May12.023959.20121@sophia.smith.edu> jfieber@sophia.smith.edu (J Fieber) writes: >>SETTING: >> A UM486V AIO motherboard -- >> - 33MHz 80486dx >> - 6 ISA, 2 VL-bus slots >> - 256k external cache >> - local-bus IDE controller w/ connor 240 meg drive >> - floppy controller >> - 2 serial, 1 parallel, 1 game port >> - AMI bios > >HOW MUCH RAM? You imply 8M; if >16, there will be problems. Reduce to >16M or below and retry. That would be 8 meg. Sorry I forgot to mention it. >[ ... ] >[ BUS ON TIMES ] >> Would some kernel hacker tell me how to adjust this properly?) >[ ... ] >>ADAPTEC CONFIG: > >This is where you diddle tyhe bus-on times. Unless you have recompiled >the kernel, you will have a hard time reducing bus-on time. I believe >that someone else had this problem (Nate?) and it's now working for him >with about a 50% reduction in on time. No. The 1542C has no "user" adjustment for the bus on/off time. DMA speed, yes. There are no jumpers on the board aside from disabling the floppy and setting the address. I stuck a couple lines of code in the aha1542.c file just before the bus speed that *supposedly* set to set the bus on/off time. The default values are (according to the adaptec tech support person) 11 and 4 respectively. I reduced the on time and increased the off time but observed no change. I certainly could be doing something wrong though; I'm far from being a seasoned kernel hacker. Also, if the problem is memory, rather than taking a performance hit I'd squeal in the ear of the dealer and demand decent memory since the machine is new. >The problem in his case was that the DMA refresh wasn't getting done. >You may want to jumper more wait states onto the motherboard to see if >this will help. If the wait states do the trick, you should be able >to load and recompile with your now heavily-sedated machine. If adding >wait states doesn't help, then it'd not the bus-on time. The wait-states are set in via software. I've tried cranking them up to the max setting. No help. :( Rebuilding a kernel isn't a problem as I have a functioning IDE drive. >Also: who is the manufacturer of your extern cache silicon? I probably I don't know without taking apart the machine but since I still had the problem with it disabled I would suspect the cache would not be the problem. (Feel free to disprove me though...) ****** I've a question about SCSI geometry and disklabels. When 386bsd boots up, the aha1542 code reports a geometry. Is that the geometry I should use for the disklabel? It certainly is different that the geometry I used for the same drive when it lived in my Amiga. I also just noticed something strange in the disklabel. If I have partitions `a', `c', and `d', it reports that there are 4 partitions. Is it counting the `b' that I didn't put in? Must I put a `b' partition in? The only way I could label the Quantum PD210S was to edit the one that it invented when it found none. newfs most definately did not like what it found there. I think I'll go through the comp.os.386bsd.* archives looking for info on SCSI problems... Finally, I thought that I was having problems with the tape drive as well. Pending further testing, that *may* prove to be false. This makes me even more suspicious about geometry and disklabels. -john -- === jfieber@sophia.smith.edu ================================================ ======================================= Come up and be a kite! --K. Bush ===