🚀 go-pugleaf

In article <BwG9HK.HKq@acsu.buffalo.edu> chifang@sybil.cs.Buffalo.EDU (chi fang) writes:
 >
 >         We have been adding external SCSI-2 FAST (10 MBytes/sec)
 >         disks to our new SPARCstation 10. We can achieve reliable
 >         operation
 >         of one external SCSI-2 fast disk, but when we operate
 >         more than one device externally we see data errors
 >         and can't operate the disks in the SCSI Fast (10 Mbytes
 >         /sec) mode.
 >
 >         We have checked the usual cables, terminators, etc. and
 >         we believe we are following all the rules.
 >
 >         Any comments appreciated.   Anybody else having similar
 >         problems?????


Are these drives differential or single-ended? The SCSI-2 spec only allows
Fast transfers using the differential option. Lots of people are pushing
single ended to 10 MB/sec, but there are many things that can make it not
work. There is no set standard of exactly what is required to do Fast
single ended, but there is a proposal that I think will be included in
SCSI-3 with a set of guidelines to make it possible. Until then, here is
a few things you can do to make it work better: use active negation drivers
to provide the bus with a clean signal, use input filtering, use Alt-2
termination, keep the cables short, use good cables, limit the number of
devices on the SCSI bus, etc. I realize that some of these are not under
your control but under the control of the protocol chip manufacturer, but
some of them you can control.

So if you are using differential it should work, but with single-ended
it's hard to say if any particular configuration will work for sure.

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