Date: Thu, 19 Jan 1995 17:25:41 -0800 From: rsoles@SIRIUS.COM (Roger L Soles) To: Plyaskin Sergey <splyaski@cmp.com>, "'freebsd-questions@freebsd.org'" <freebsd-questions@FreeBSD.org> Subject: Re: FreeBSD/Adaptec 1740 problem Message-ID: <9501200119.AA01353@SIRIUS.COM>
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My suggesttion was based on empirical data... Under FreeBSD I haven't seen a problem... but under OS/2 (which like BSD can drive the SCSI bus fairly hard) I've had intermitent problems with the AHA-1742, AHA-2742T, AHA-2842, and AHA-2940 when I don't use terminator packs -- when I do, it seems to work well... DOS never seems to have this problem, my guess is that there's plenty of time between SCSI bus acesses... I can't image what the reason is, unless it has something to do with noise on the SCSI bus... - Roger At 04:20 PM 1/19/95 PST, Plyaskin Sergey wrote: > >Okay, it makes sense to try using a terminator pack, thanks. >However, I still do not understand why it worked with DOS/Windows. And >regarding (4): how does it affect the performance? I have set 5MB/s already, >and it doesn't help. >Thanks. > >Serge > ---------- >From: rsoles >To: Plyaskin Sergey; 'freebsd-questions@freebsd.org' >Subject: Re: FreeBSD/Adaptec 1740 problem >Date: Thursday, January 19, 1995 10:07AM > >I'd guess it's a termination problem. > >1 - make sure you're running the 1740 in enhanced mode (eisa config > if necessary) >2 - make sure you've got each physical end of the chain terminated with > no termination in the middle >3 - consider using a terminator pack rather than the termination built > into any device (if the host adapter is at the end of the chain > it should be ok to use it's termination). >4 - if nothing else works, slow down the maximum transfer rate for those > devices (using your eisa config) > >At 09:49 AM 1/19/95 PST, Plyaskin Sergey wrote: >> >>I've been running FreeBSD 2.0 on a Gateway 2000 486SX25 ISA machine with no > >>problems for about 2 months. It has an Adaptec 1542CF SCSI host adapter and > >>one external 1Gb SCSI HD. >> >>Now, I have problems installing FreeBSD on a Mitac 486DX33 PC with EISA >bus. >>It has EISA Adaptec 1740 SCSI host adapter and 2 SCSI hard disks. Under >DOS, >>everything worked fine. I decided to get rid of DOS and install FreeBSD. I >>deleted all patitions on the disks using fdisk and started installation. >>When starting the computer, I get a message indicating that both HDs are >>detected: >> >>SCSI ID0 Installed >>SCSI ID1 Installed >> >>however, FreeBSD finds only the adapter but not the disks. I tried both >>FreeBSD 2.0-RELEASE and FreeBSD 2.0-950112SNAP. I also tried to set the >>adapter to both standard and enhanced mode (in standard mode it's detected >>as 1540.) I borrowed an Adaptec 1540 (ISA) from my friend, and the disks >>were detected by FreeBSD. >> >>Is that the problem with that particular 1740 adapter or EISA adapters in >>general or I do something wrong? I'm confused and would appreciate any >>help/hints. >> >> > ---------------------------------------------------------------------------- > >> ----------- >>Serge Plyaskin splyaski@cmp.com >>Advanced Technology Center 516-562-5951 >>CMP Publications >> > ---------------------------------------------------------------------------- > >> ------------ >> >> >//-------------------------------------------------------------------------- > -- >// Roger L Soles >// PO Box 280785 >// San Francisco, CA 94124-0785 > > > //---------------------------------------------------------------------------- // Roger L Soles // PO Box 280785 // San Francisco, CA 94124-0785
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