SCSI Questions

[Aaron <heiss@SDF.LONESTAR.ORG>]

I'm planning on setting up a SCSI hard drive.  I have several external
drives, but all are in unknown operating condition, so I'm not positive
that I'll know when I have everything set up correctly.  As such, I'm more
than a little concerned that I get the hardware settings right!

My SCSI card is one of the earlier Apple parts.  It's labelled "APPLE II
SCSI CARD" and has a copyright date of 1986; the ROM chip is labelled
"341-0437-A", and is copyrighted 1987.  It also has a block of eight
jumpers, the rightmost of which (which connects pins 8 and 9) was set when
I got it.  Otherwise, all are open.  I'd like to know what these jumpers
do, and which need to be set, before plugging this thing in!

Also, I understand that only certain SCSI cards can handle CD-ROM drives.
I've heard that, of Apple's SCSI cards, only the High-Speed and the
original version Rev C were capable of CD-ROM interface.  I've also read
that the ROM chip on this card is Rev C.  Does that designation then carry
over to the card as well, or is a Rev C card different from an earlier one
with a Rev C ROM?

Finally, I'd like to know how many and which type of terminators I'll need
to use, for each setup.  If I'm not mistaken, I should just need a simple
terminator on the unused port of the hard drive, if that's all that I have
connected to the computer, but I've read conflicting things about how to
set terminators if I add a CD-ROM drive to that (assuming, of course, that
my SCSI card can handle it!).  Do I use an additional pass-through
terminator between the hard drive and the CD-ROM drive, or between the
computer and the device closest to it on the daisy chain, or none at all?

Any answers to these questions will be much appreciated.  Thanks in
advance!


Aaron Heiss

heiss(AT)sdf(DOT)lonestar(DOT)org
heiss(AT)pdx(DOT)edu (preferred address)
http://web.pdx.edu/~heiss

SDF Public Access UNIX System - http://sdf.lonestar.org