SCSI Bus Problem?

From: Richard Erlacher <edick_at_idcomm.com>
Date: Mon Feb 11 20:07:02 2002

That doesn't have to be the case if you are careful about your cabling and
termination. I've got narrow (50-contacts), wide (68 contacts), and
"ultra-wide" (SCA-80) devices all on the same cable with the appropriate
adapters. The performance of each device doesn't seem to be much different
from the same device on a cable with only that "width" on it. Multiple
devices being tested (via the ADAPTEC SCSIBENCH.EXE program) seem to operate a
mite slower than the same devic alone.

If you fail to terminate the upper data bits, fail to set the jumpers
correctly, or fail to sequence the devices correctly on the cable, performance
will ordinarily be compromised. My FUJITSU SCA drives respond to the data
jumper on its control board, but performs quite admirably as an 8-bit device
when given an 8-bit transfer configuration via software even though cabled and
terminated for 16-bit operation.

YMMV, I suppose.

Dick

----- Original Message -----
From: "Geoff Reed" <geoffr_at_zipcon.net>
To: <classiccmp_at_classiccmp.org>
Sent: Monday, February 11, 2002 3:42 PM
Subject: Re: SCSI Bus Problem?


> At 12:34 PM 2/11/02 +0000, you wrote:
>
> >SCSI Wide also supports plain old SCSI devices. I'm running such a
> >configuration in my web server (3 SCSI Wide drives and 2 SCSI-2)
> >
> >Sellam Ismail Vintage Computer
Festival
>
> Yup, sellam's right, be warned however that your SCSI bus will be hobbled
> to the speed of the slowest device usually.
>
>
Received on Mon Feb 11 2002 - 20:07:02 GMT