SCSI Interface in the 3/80

[Howard J. Postley]

In article <3915 at kalliope.rice.edu>, ely!haerle at rutgers.edu (Mark Haerle) 
writes:
> The local sales rep indicated SCSI-1 and SCSI-2 devices may not be mixed
> in a Sparc Station-1. The internal hard disks and the external storage
> packs are not compatable with the old shoe boxes. You may run one standard
> or the other, but not both on the same SCSI interface. The SCSI-2 has a
> faster transfer and may also have a different command set.

I wish that Sun had not decided to call things SCSI-1 and SCSI-2 because
SCSI-2 is the newer SCSI definition that can deal with faster transfers
and wider data paths.  That's not what Sun uses them to mean.  But I
digress before actually getting started what what I wanted to say.

The difference between Sun's SCSI-1 and SCSI-2 is that -2 supports
syncronous transfers.  The drives which support sync-SCSI contain a
superset of the async-SCSI command set.  There is no SCSI reason that the
drives can't be mixed, I have done that many times.  In fact, the 3.5"
quantum drives, which are internal to the SS 1 are not sync-SCSI but the
327 is.  If you hook a sync-capable drive to an async only interface, it
just speaks slowly - but it still works fine.

Anyway, I have setup SS 1's with both internal disks and an old shoebox so
I know it works.  I don't know what your sales rep was refering to.

//hjp


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