Re: SCSI II on IIgs?

[dempson@swell.actrix.gen.nz (David Empson)]

In article <2C5C4739.20920@ics.uci.edu> jimmys@ics.uci.edu (Jimmy Shaw) writes:
> In article <93Aug1.110204-0600.138432@amisk.cs.ualberta.ca> glyn@cs.ualberta.ca writes:
> >I understand that SCSI II devices will work with SCSI I cards, but
> >will just not perform to the best of their abilities.  Question:
> >Have there been any plans to produce a SCSI II _card_ (such as a
> >RamFast upgrade) for the IIgs (or II in general)?
> 
> I could be wrong, but aren't the capabilities of SCSI II way over
> the GS's (the '816's and the bus') capabilities?  Then what's
> the point, since the GS can't handle all the new found power of
> SCSI II, we might as well not have it in the first place.

No, you're thinking of "Fast SCSI" and "Wide SCSI", which are special
features available under the SCSI II standard.  A SCSI II device must
still comply with the original SCSI I bus, so you can connect it to an
older controller card (provided the card follows the standards well
enough).

The main problem you'll run into is much stricter rules about
termination.  SCSI II devices tend to be a lot more fussy about supply
of terminator power and other issues.

The most important feature of SCSI II is further standardisation of
device command sets, which means that a generic driver could be
written to support most devices of a particular type.
-- 
David Empson                                                               
dempson@swell.actrix.gen.nz                                                
Snail mail: P.O. Box 27-103, Wellington, New Zealand