Subject: Re: Expanding scsi A bus cable in MV/VS3100 class machines to 5 devices
To: None <arcarlini@iee.org, port-vax@netbsd.org>
From: DCGrendel <dcgrendel@consolevision.com>
List: port-vax
Date: 02/12/2004 12:10:39
Antonio Carlini wrote:
>If OTOH you have a VAXstation 3100 M76, then the internal
>cable is "special" and is actually two cables one of which
>servers the internal devices and the other connects
>to the external connection. I've never needed to look
>too closely at this, so I don't know how tricky it would
>be to replace with some home-brew arrangement.
>
>
The internal cable on the M76 has the following:
3 female 50 pin headers
1 male 50 pin header (used for terminator)
1 female 100 pin high density header
1 external (50?) SCSI
>>The only way I can see easily to do it is to cut
>>the cable, and, using 50 pin dip headers, patch
>>in a section of ribbon cable into the loop that
>>is sufficient to reach all 5 internal devices.
>>
>>
>
>I'd be tempted to leave the existing cable untouched
>and just make your own ribbon cable plus connectors.
>I've made them up in the past (without any test equipment
>to tell me if they were within "spec" or not) and
>they've worked perfectly well for me (on PCs rather than
>VAXstations, but for this era I expect it's the same).
>
>I assume that the correct ribbon cable and connectors
>are available still (otherwise you cannot even splice
>anything in!)
>
>
if you have a normal 4 drive ribbon cable, you can plug it into the
terminator socket,
and then supply a different terminator on the end of the cable.
another solution which I have used often is the 50 pin dssi ribbon cable
from a
uvax3600 in a BA213 since it has 3 more male and one female and all
wires are present.