Subject: Re: SCSI and VS2000/MV2000/MV II
To: None <port-vax@NetBSD.ORG>
From: Tim Shoppa <email@example.com>
Date: 08/02/1995 10:05:02
> 2) I've got a MicroVAX II, so I think the NFS option is my only option.
> Or, is there a SCSI card (even if you can't boot) for the Q22 bus?
There are plenty of SCSI cards for the Q-bus. Good ones cost a lot,
but are worth it; I've got a CMD CQD-440 M/T in a BA213 with my KA650,
and it's the best thing since sliced bread. It runs several SCSI-2
disk drives, a DLT tape drive, a CD-ROM drive, and occasionally
a 4mm or 8mm tape drive.
There are older SCSI cards on the used market; they cost a lot less
than a new CMD SCSI controller, but may not offer as much versatality.
Emulex and Sigma are common names. Andromeda still makes new Q-bus
SCSI controllers, but they're primarily selling to the OEM market.
All Q-bus SCSI controllers that I'm aware of emulate MSCP-type devices, and
thus *should* be absolutely software compatible with RQDX3/KDA50/UDA50
type controllers, assuming that your software isn't tied down to any
particular features (like software-initiated bad-block-replacement)
of any one of these devices. All Q-bus SCSI controllers I've ever used
can be directly booted from the console of a uVax.
For less money, you can find ESDI and SMD controllers for the Q-bus.
For example, I've got a Sigma controller that runs 4 ESDI drives in
my uVax II and emulates MSCP disks. Some SMD controllers emulate
MSCP (the Emulex QD3x series are the ones I'm most familiar with),
but others emulate massbus RM or RP disks (like the Emulex SC03).
You probably want to stay away from the massbus emulation if you have
a Q-bus VAX; I've never seen a Q-bus VAX that supported a bootstrap
from a massbus-type device, in particular. (I'm sure you could write
5.25" and 3.5" ESDI disks are still readily available, but are often
not as cheap per megabyte as more modern SCSI disks. After you figure
in the fact that a Q-bus ESDI controller is probably going to be cheaper
than a Q-bus SCSI controller, though, it may be cheaper to go with ESDI.
SMD disks are not awfully rare, but as they were never popular at all
on PC-type platforms they aren't as easy to find as ESDI drives.
It's not awfully hard to find later generation SMD drives like the Fujitsu
M2344, but you won't find them at places that deal with PC-surplus;
SMD drives were more commonly hooked to high-end minicomputers from
5 to 10 years ago. I've seen the M2344 (500 to 550 megabytes, depending
on formatting) offered for sale on usenet for as low as $25.00, but
it'd probably cost more than that to ship it... And, of course,
it's not hard at all to find Fujitsu M2351A Eagles that still work, but
they weigh about 120 pounds. I know of many shops that still run Eagles
24 hours a day 365 days a year because they've found that they're more
reliable than any modern 3.5" SCSI drives with hokey MTBF numbers.
Kellogg Radiation Lab, Caltech.