Date: Sun, 20 Feb 2000 14:59:54 -0500 From: Doug Ledford <dledford@redhat.com> To: Philipp Scherer <scherer@jupiter.t30.physik.tu-muenchen.de> Cc: aic7xxx@FreeBSD.ORG Subject: Re: Message-ID: <38B047BA.2A66E716@redhat.com> References: <200002201835.SAA15086@saturn.t30.physik.tu-muenchen.de>
next in thread | previous in thread | raw e-mail | index | archive | help
Philipp Scherer wrote: > > Re:timeout hang on boot > > ok i will look then for scsi termination problems again. > could it be a problem that i have a T-like configuration > of the 50 pin narrow branch? With the ribbon that came > with the mobo there is a connection from the 50 pin connector > on one side to the cdroms and on the other side to the external > connector which is connected to the zip drive. > > zip(term.)----ext.conn.-----host ad.(auto)--cdrom----cdrom(term.) This is almost guaranteed to cause problems. First, I'm not sure, but I wouldn't be the least bit suprised if termination were always enabled for the 50 pin interface, even when set to auto. That would over terminate the bus. Second, I wouldn't be suprised if your total cable length exceeds the 1.5m maximum cable length. Third, the typical 25 pin connector on the zip drives and the zip drive cables interfere with the transmission wave properties of a SE SCSI bus, so that can cause additional errors on faster devices (the zip drives don't care because they only run in async mode, but they went so cheap on construction that you almost can't put a zip drive on the same SCSI bus as anything else, which pisses me off, especially if you are anywhere near your cable length limits and any other device wants to run in sync mode). -- Doug Ledford <dledford@redhat.com> http://people.redhat.com/dledford Please check my web site for aic7xxx updates/answers before e-mailing me about problems To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe aic7xxx" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?38B047BA.2A66E716>