Re: Apple rev A SCSI?

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

Randy Shackelford <shack@deimos.frii.com> wrote:

> In article <529iuj$vlr@dove.qut.edu.au>,
> Willie Yeo <yeo@pigeon.qut.edu.au> wrote:
> 
> >: I got an Apple SCSI card, not a High Speed, newold stock.  The problem is
> >: that its not a rev C.
> >
> >: Is the revision a matter of a chip swap or is it a different card?  I
> >: could put this card to use in a GS or a //e if I could upgrade it.
> >
> >     Chip swap |8)
> >
> >     If you are lucky, your local Authorised Apple Service Centre might
> >do it for free ! And if you are using GS/OS, you MUST upgrade to Rev C.
> >Otherwise, you can still use the Rev A ROMs..
> 
> So does anyone know what's different in revs A, B, and C?

I don't have a full list.  The most obvious difference is that the
revision C ROM has twice the capacity of the A and B ROMs (16KB instead
of 8KB - the card supports both ROM sizes without modification).

The main features added in the revision C ROM:

- support for Apple CD-ROM drives (earlier versions only support hard
drives).

- some SmartPort commands were changed to match the developing
standards.  In particular, the call which is used for EJECT on other
SmartPort controllers now does an EJECT rather than a FORMAT!!!!

-- 
David Empson
dempson@actrix.gen.nz
Snail Mail: P.O. Box 27-103, Wellington, New Zealand