VAX 11/725

From: Ethan Dicks <>
Date: Sun Dec 5 04:00:53 2004

On Fri, 3 Dec 2004 20:05:14 -0500, Heinz Wolter <> wrote:
> "RL02 / R80 drive combo"
> That was what shipped with the 730.. the same beast in
> 19" rack clothing.

Yep... the HD is also called an RB80 (to distinguish it from the RM80
and RA80)... is still marked "R80" on the front, though. Those aren't
as robust as an RL02, but plenty more robust than many RA81s... shame
it's only a DEC-proprietary pseduo-SMD interface... no other drives
work with it. For the weight and power consumption, an "RB-81"
wouldn't be the worst thing in the world to ever have existed. OTOH,
if you could _afford_ an RA-81 back in the day, you probably weren't
likely to hook it to a CPU that cost _less_ than the drive (price
point: RA81 in mid-1984 was ~$24K US, I _think_ an 11/730 was $30K at
release, but I could have mis-remembered; the 11/725 was always less
than the 730, but license costs were probably similar ($10K?))

AFAIK there's nothing preventing one from installing the IDC card into
a 11/725 and hooking up a real RL02 up... would still be DQA1: to VMS
AFAIK. Could even boot SA backup and/or diags from it. Given that I
saw lots of boards in the KA730 set die and never saw on e dead IDC,
it might not be too hard to find a spare somewhere - and the RL02
cable is the standard 40-pin one like you see on the RL11.

> the 725 has a dual inter/external RC25-
> an oddball drive sharing the same spindle for the internal as the
> external.. Obviously not as nice as a stock RL02 since if it breaks..
> the 725 is toast.. unless you have external disks..

Right. Also... can't change removable platters on RC25 if booting
from fixed platter because of shared spindle. Another reason for
external drive (or Unibus SCSI and _internal_ 3.5" drive... power
wouldn't be an issue there!)

Received on Sun Dec 05 2004 - 04:00:53 GMT

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