Re: Quantum Fireball with Ramfast

[david@wraith.cc.uow.edu.au (David E A Wilson)]

nparker@cie-2.uoregon.edu (Neil Parker) writes:
>Note that the option to skip arbitration is not allowed in the SCSI-2 specs.
>All SCSI-2 initiators *must* do arbitration.  However, a SCSI-2 *target* may
>optionally support non-arbitrating initiators, for compatibility with SCSI-1
>initiators.  The same thing is true of the option to support the SCSI-1
>"single initiator option" (which, I suspect, is how the RamFAST manages not
>to have a SCSI ID)...a SCSI-2 initiator may never use the "single intiator
>option," but a SCSI-2 target may optionally support it for compatibility
>reasons.

>Disclaimer:  The above discussion is my own interpretation of the SCSI draft
>docs.  I don't have copies of the final SCSI standards.  I doubt much changed
>between the last drafts and the published standards, but you never know...

Looking at my copy of the SCSI-1 standard (X3.131-1986) the paragraph in
question reads:

5.1.3.4 Single Initiator Option. Initiators that do not implement the
RESELECTION phase and do not operate in the multiple initiator environment
are allowed to set only the target's SCSI ID bit during the SELECTION phase.
This makes it impossible for the target to determine the initiator's SCSI ID.

So I for one would agree with your interpretation. Before this topic came up
here I would not have believed it possible for a SCSI bus to have 8 targets.
-- 
David Wilson	Dept CompSci Uni Wollongong Australia	david@cs.uow.edu.au