[Info-vax] SCSI cable rules.

[Scott Dorsey]

Tom Adams  <tadamsmar at gmail.com> wrote:
>We have DS10s and I am trying to avoid SCSI cable pitfalls.
>
>I have some SCSI cables with no terminator on the end, it was probably a mi=
>stake to buy those.  Looks like most of the disks and tape drives we have d=
>on't have a "terminator" jumper.  Some have "term power" jumpers. The passi=
>ve female terminators for internal 68 pin cables seem to be kind of pricy a=
>nd bulky.

Use external terminators.  If you install termination blocks inside devices,
sooner or later someone will screw up configurations.  Stay away from cheesy
cables with internal terminators.  Use the external terminators with the male
connectors.  Plug one into the end of the daisy chain.  Keep it simple.

>Can I assume that all the SCSI control cards that work for a DS10 will prov=
>ide term power so that I don't have to add a device that has term power?

Anything with scsi-3 will likely provide termination power.  Some devices with
scsi-2 will, others won't.  If you're using a passive terminator you won't need
termination power.  If you're using an active terminator you will.  Use the
correct terminator for the kind of buss you are using.
--scott
-- 
"C'est un Nagra. C'est suisse, et tres, tres precis."