SUMMARY: B-Y-O SCSI card mystery [REPOST]

[v-paulk@microsoft.com (Paul Kearns)]

It's come to my attention that my original summary never made it off my
news server.  I apologize for getting the summary out three weeks after the
original posting.  Better late than never, I guess.

Since I got a number of "me too"'s, I'm posting this summary in the hopes
of helping someone else through a similar problem.

To refresh, the problem I was having:  I bought a Quantum ProDrive 105S
SCSI drive.  After installing the drive in a case/power supply and
connecting it to my //gs via a Apple High Speed SCSI card, nothing would
recognize the drive, including both GS/OS and the P8 utilities that came
with the SCSI card.

Thanks for solutions and suggestions go to the following people.  My
eternal gratitude is extended to you all -- let me know if there's ever
anything I can do for you.  I really appreciate the ability to borrow from
the collective intelligence of Usenet, especially since Apple // support is
getting harder and harder to find locally.

	Petar E Puskarich <ppuskari@magnus.acs.ohio-state.edu>
	Steven T Chiang <stc7@cunixb.cc.columbia.edu>
	Steven Nelson <snelson@umaxc.weeg.uiowa.edu>
	dennis@ihlpl.att.com (Dennis Dale)
	voss@i40s19.ira.uka.de (Stefan Voss)
	irsman@iastate.edu (Ian Schmidt)
	goo@cwis.unomaha.edu (Kent Radek)
	taob@r-node.hub.org (Brian Tao)
	jbardt@trumpet.calpoly.edu (josh)
	arb@sunsrvr3.cci.com (Anthony Bean)
	Brian Scully <bscully@xenitec.xenitec.on.ca>
	David.Empson@bbs.actrix.gen.nz (David Empson)
	Fan Li TAI <USTAI@msuvx2.memst.edu>
	ALBRO@vaxe.niehs.nih.gov

SUMMARY
=======

Many people reminded me to install the SCSI drivers onto my GS/OS startup
disk.  This is necessary to have GS/OS see the drive, but I was having
trouble seeing the drive at all.  If the SCSI card utilities can see your
drive, but GS/OS can't, make sure you do this.

One gentleman indicated that he couldn't initialize his drive with the
System 6.0 ADU, but the System 5.4 ADU would see it.  I suspect indiviual
incompatibilities here.  Note this wasn't really my problem, as in the
above paragraph.

A couple people suggested swapping out the drive, the card, and the
computer.  I did this as much as I was able, with no luck.  I figure
anyone having trouble would have already tried this as much as possible.

Make sure to have the correct addresses set on the card and the device --
each SCSI device, including the interface card, needs to have it's own
distinct "address".  This is a number (0 to 7) relating roughly to device
priority.  It's usually set with three jumpers or DIP switches.

Each end of a SCSI chain needs to be "terminated".  These terminators
absorb the used SCSI packets so they are not re-interpreted.  The Apple
High Speed card and the RAMFast apparently are terminated themselves, but
the original Apple Rev C card needs an external terminator.  Other SCSI
devices may or may not be terminated internally -- check your manual.  Make
sure, however, that there are ONLY two terminators (internal OR external),
one at either end of the chain.

The solution to my problem was something similar.  Termination POWER!
Apparently the terminators mentioned above require +5V to operate
correctly.  The Apple // cards, as well as the original Macs (Mac Plus, etc)
do not provide this TPWR, because of power supply limitations.  If a drive
(or other SCSI device) in the chain does not provide +5V on line 26, the
terminators will not work and the chain will not terminate.

The best solution, of course, would be to only use a drive that provides
termination power (the Quantum drive does not).  I worked myself around the
situation by leading +5V from the power supply I was connecting the drive
to onto the SCSI cable.  It's only a patch, but it solved the problem.  If
you aren't afraid of some electrical hacking, this might also work for you.

Someone also mentioned that certain SCSI cables made for CMS cards have pin
40 disconnected.  This is an anomaly of the CMS SCSI system, I think.

A couple people mentioned that they had luck using ONLY the drive in the
SCSI chain (which I was doing anyway).  I don't know if that's really
necessary or not; I suspect that probably these people might be adding two
or more internally terminated devices to the chain, giving too much
termination.  Remember to remove the terminators from your devices if you
don't need them.

And that's about everything (whew!).  If anyone is in the same boat, but
doesn't understand this summary, feel free to send me some mail.  I can't
promise anything, since I'm new to this, but I've certainly learned a thing
or two about SCSI in the last three weeks, so...

Once again, thanks to everyone for their help.

Paul Kearns
v-paulk@microsoft.com