Re: SCSI card options

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

Benjamin O Zotto <zotto@nospam.fas.harvard.edu> wrote:

> 1. I understand from the FAQ (etc) that the two "real" options for SCSI
> interfaces are the RamFAST card and the Apple HS SCSI card.  However, I
> was wondering about the older Apple SCSI cards.  I know there are three
> revisions and I've heard rev. C being described as "passable" but what about
> the older two?  Are they essentially useless?  Would one never bother with
> a revA or revB?

The "revision C" referred to with the original Apple SCSI card is the
firmware revision in the EPROM on the card, not the hardware revision of
the card itself.  You can upgrade a revision A or B SCSI card to the
revision C firmware if you can get hold of a copy of the ROM image and
have access to an EPROM programmer.

The main reason that revisions A and B are frowned upon is that GS/OS
will refuse to operate with them.  The other reasons which occur to me
are:

1. There is a rather nasty coincidence with the SmartPort firmware
interface in revisions A and B: the call number which means "Eject
volume" for most SmartPort devices is defined as "Format Device" for the
SCSI card.  If a program blindly tries to eject a disk without checking
for the SCSI card, it will wipe your hard drive.

2. The revision A and B firmware have no support for CD-ROM drives.
They only support hard drives.

Even revision C is rather limited: it doesn't know about removable
devices like SyQuests and Zip drives, so it isn't safe to eject these
devices while running ProDOS-8 (GS/OS is OK, because you are using the
GS/OS drivers rather than the firmware on the card).