VanLUG Email Archive
Dave Martindale (davem@groucho.cs.ubc.ca)
Sun, 9 Jan 2000 20:40:06 -0800
Curt Sampson <cjs@cynic.net> writes:
>I suspect that had it not been for penny-pinching on the part of
>some vendors, differential SCSI would have been much more common
>all along, and a lot of people would have saved a lot of hair when
>trying to diagnose problems with a SCSI bus.
There has been a bunch of penny-pinching and bad implementations.
I blame Apple for a bunch of that, with the stupid 25-pin SCSI
connector on the back of Macs for a decade. (There's supposed to
be a separate ground wire for every signal wire, and you can't do
that in a 25-pin connector). Even now, some scanners come with
SCSI adapters with 25-pin connectors, and the SCSI Zip drive does
it too. After long experience, I tend to classify any SCSI peripheral
with 25-pin connectors as "junk" - at least if you want a SCSI chain
that works when more than 1 or 2 devices are on it.
Most "consumer grade" external SCSI cables don't have all 50 wires in
them either, but the cheap ones don't even use an individual wire for
each ground pin - they jumper several together. See "junk" above for
my opinion of these.
Fortunately, internal SCSI cables are much better - they just use
plain ribbon cable with all 50 conductors (or 68 for wide).
Dave
-- This message came to you via the Vancouver Linux Users Group mailing list. For unsubscription instructions do not email the list, but rather send mail to <vanlug-request@gweep.bc.ca>.
This archive was generated by hypermail 2.0b3 on Mon 10 Jan 2000 - 04:40:34