#Help With SCSI Drives
6 messages in this thread
#Help With SCSI Drives — declared parent_msg_num=(none), resolved parent_id points to #(none)
A friend and I have come across a problem we can't seem to resolve. He is
trying to connect TWO SCSI Hard Drives to a Commodore A2090A. We've both
read the docs thoroughly but are still having problems. He needs to set
the Logical Unit Number for each of the drives. I was assuming it was done
in the mountlist but I can't find any examples.
Does anyone here know how to handle this situation? I have a 2091 which
does things considerably differently, like it doesn't need the mountlist.
He has two Hewlett Packard drives which are supported by just about
everyone. They have been checked out by Hewlett Packard and they are both
operating properly. We just can't seem to figure out how to handle the
LUN's for the two drives.
Thanks in advance for any help given, it is certainly needed.
Keith E. Coldiron
P.S. Has anyone managed to get an HP LaserJet III to work with a parallel
cable longer than 10 feet? I just got the printer and found that it
wouldn't work with a 12 foot cable but it works fine with a 10 foot one.
Their manual clearly states 10 feet to be the max but I was surprised to
find 12 feet to be a problem. Anyway it's just one for someone to file
away until it happens to someone else!
#3198-Help With SCSI Drives — declared parent_msg_num=3198, resolved parent_id points to #3198
Keith –
I believe the 2090A handles multiple SCSI IDs just fine, but it can't
handle multiple LUNs off of a single SCSI ID. The SCSI ID is usually set on
the drive by a jumper; I'm not familiar enough with the 2090A software-wise
to say what's needed in MountList.
Harry
#3217-#Help With SCSI Drives — declared parent_msg_num=3217, resolved parent_id points to #3217
Harry,
Thanks for the input, we'll look into that one. I hadn't even thought of
it. I did remember the SCSI drives for Mac's using an ID on the drive
itself. I tell my friend to look for something on the drive itself.
Keith
#3259-Help With SCSI Drives — declared parent_msg_num=3259, resolved parent_id points to #3259
SCSI drives on the mac do have SCSI ID selection either as a hidden DIP
switch or as something more mac-like. Like Amigas, macs use SCSI ID 7 (oh
oh is it really 6 Ethan?) for their own so use some other number.. the
logucal unit number is the numbe after UNIT in the mountlist, like the 2 in
df2:.. I think gaving the same device (i.e. hddisk.device)
two things with the same unit would get pretty ugly pretty quickly, but if
you try it, let us know what happens
#3198-#Help With SCSI Drives — declared parent_msg_num=3198, resolved parent_id points to #3198
Keith,
The A2090(a) handles multiple SCSI drives just fine…I've got 2 on
one right now.
You are talking about setting LUNs (Logical Unit Numbers)…a
couple of things here. First, the A2090 driver software doesn't support
LUNs, but 2nd, even if it did support LUNs, you're not using them right.
On the SCSI bus, there can be a total of 8 devices attached
directly to the bus…the host adapter card (the A2090) counts as one
device. Of those 7 remaining devices, each must have a unique SCSI ID that
will be between 0 and 7 (the host adapter again takes one of those
numbers…usually 7 or 0).
Then, if the software/hardware combination supports LUNs, one of
those devices attached to the SCSI bus can have multiple devices attached
to itself. Those devices would have unique LUN's for that device.
That is…at SCSI ID 6, you could have LUN 1, LUN 2 and so forth,
you could also have a LUN 1 and LUN 2 at SCSI ID 5. In fact, every devices
on the bus has at least one LUN #…LUN 0 for the first device at that SCSI
address.
Since those drives you have each represent a separate "tap" on the
SCSI bus…they need to have their SCSI ID set so they're different.
If you're familiar with the older IBM style hard drives and hooking
them up…setting SCSI ID is much like setting the DRIVE ID on thos older
drives.
Also, the SCSI bus must be properly terminated. The last drive on
the bus must have it's terminators installed, drives in the middle must
have them removed.
Don
#3250-Help With SCSI Drives — declared parent_msg_num=3250, resolved parent_id points to #3250
Don,
Thanks for all the information on SCSI drives. I'll pass this along to my
friend and see what happens. He lives about 1,000 miles from me so we do
these things by phone ($) and he doesn't have a modem. I'm not even sure
the part of Colorado he lives in has access to a net so I help out. I'll
let him know what to look for. You also helped me a lot as I didn't really
know a lot about SCSI devices, thanks. Keep up the good work, it is
appreciated.
Keith