[net.unix-wizards] RA81 or RM05?

rob@genrad.UUCP (Rob Wood) (07/06/83)

We are in the process of configuring a new Vax.  One of the questions is
whether to go with the economical RA81/UDA50 or the proven RM05.  You can
tell by my adjectives what the major considerations are.  If you were
given the chance, what would you do?  Any other thoughts?  We have already
decided definitely on DEC drives.  I'd appreciate prompt replys.  Thanks.

	Rob Wood	(decvax!genrad!rob)

ron%brl-bmd@sri-unix.UUCP (07/09/83)

From:      Ron Natalie <ron@brl-bmd>

Actually, I'd go with the RA81/HSC50's that DEC
just announced availability on.

-Ron

gwyn%brl-vld@sri-unix.UUCP (07/10/83)

From:      Doug Gwyn (VLD/VMB) <gwyn@brl-vld>

The only drawback to the HSC50 that I can see is that I suspect there
are no device drivers for it!  From what I've seen of UDA50 drivers so
far, they were not designed to support the general Digital Storage
Architecture.  I would love to be proved wrong about this...

FRANK%utah-20@sri-unix.UUCP (07/10/83)

From:  Randy Frank <FRANK@utah-20>

Having talked to both people and DEC and Berkeley about potential support
for CI bus (HSC50) based disks, the comments can be summarized as follows:

1) writing a driver for a CI based disk is more akin to writing a networking
   system than writing a device driver.  In particular, you have to
   implement a protocol called MSCP (mass storage control protocol) which
   is used over the CI bus.

2) it isn't a trivial job (i.e., don't expect one from DEC in the next few
   weeks).  It's substantially harder that simply hacking an existing
   disk device driver for a "new" disk.

3) no one will commit that they actually are going to do it, but that clearly
   it is DEC's future architecture, so in most probability it will be done
   at some time in the future, but don't hold your breath.

4) (this one's my own interpretation) Ideally what DEC would like to do
   is have Unix and VMS co-exist on the same CI bus, hopefully sharing
   disk structures.  Clearly this is an enormous project, but given DEC's
   planned support of Vax Unix is probably an intelligent thing to do.
   Whether or not it is even a reasonable thing to implement remains to
   be seen.
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ron%brl-bmd@sri-unix.UUCP (07/10/83)

From:      Ron Natalie <ron@brl-bmd>

The lack of device drives has never stopped the UNIX
community before..

-Ron