Subject: Re: pc164/ncr scsi problems
To: None <,>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: port-alpha
Date: 08/29/1999 23:53:22
>>> For reference, this drive was working, synchronous, under SunOS
>>> 4.1.4 in a Sparc LX (Fast SCSI, just not Ultra) at 10Mbit/s.
>> Also for reference, my disks were working fine _for_years_ [...]
> I hate to sound like a broken record, but 4 drives is really too many
> for a singled-ended chain, especially if any of them are external.

This is not my experience, unless you mean the comment to apply
specifically to an alpha, or to that scsi card, or some such.

I have a SS1+ at home - the machine I'm typing on right now, in fact -
that I booted with six drives on, all external:

- Micro-SCSI to DB50 cable (approx 1 metre).
- Enclosure with two disk drives and a tape drive (approx .5 metre
   internal ribbon cable).
- DB50 to DB50 cable (approx 1 metre).
- Two drives sitting loose on top of the enclosure, ribbon cable and
   connectors from a dead enclosure, powered by a pc power supply
   outside a case (approx .5 metre ribbon cable).
- Custom cable, DB50 to DB25 - interestingly, many of the DB50 pins are
   not present (presumably grounds).  This cable was made by giving the
   cable shop a pasted-together assembly of adapters and cables and
   telling them to build a single cable equivalent to it.  (Approx 2
   metres of cable.)
- SCSI-only zip drive.
- Termination done with the switch on the zip drive.

Worked fine.

And there was the setup I had on a Sun-3 with seven disks mounted
between two pieces of sheet metal, connected with a piece of ribbon
cable with seven Bergs on it...terminated by resistor packs on the last
drive.  That too worked Just Fine, though admittedly the cabling was
less questionable.

					der Mouse

		     7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B