CDC 9762 vs. RM02/03?

From: Ethan Dicks <dickset_at_amanda.spole.gov>
Date: Wed Jul 14 18:28:13 2004

On Wed, Jul 14, 2004 at 09:38:54AM +0200, Ed wrote:
> I have some conflicting info here. On one hand the literature says that
> DEC rebadged the CDC9762 as RM02 and RM03s...
>
> OTOH, the CDC has a SMD interface yet the RM02/03 has a MASSBUS interface.
>
> Furthermore, the CDC is listed to be at 80MB, yet the RM02/03 apparently
> has 67MB only.
>
> So, which is true? I'm confused.

Both... as shipped, the CDC 9762 is 80MB formatted; as shipped, the
DEC RM02/RM03 is 67MB from the same mechanism. The bottom of the
DEC RM02/RM03 is filled with DEC electronics that had a MASSBUS
interface on one end, and a 62-pin/26-pin interface that is *almost*
SMD. In reality, DEC made a couple of changes to the CDC cards in the
card cage in the back of the drive, so it's not trivial to take an RM02
and make it back into a 9762 unless you happen to have a set of original
CDC cards.

There's something about the logical layout of the RM02/RM03 that either
ignores some part of the drive capacity, or else it's using 13MB as
spare tracks. And it's not just on a real RM02/RM03; at SRC, we had
a 160MB Fuji SMD drive on our SI9900 controller as a system drive for
our VAX-11/750. It appeared to the VAX as a pair of RM03s, down to the
67MB available capacity (i.e., the driver wasn't patched to try to make
the 160MB drive _look_ like a single 160MB drive, unlike our Fuji Eagle,
that _was_ a patched RM05 to the system).
-- 
Ethan Dicks, A-130-S      Current South Pole Weather at 14-Jul-2004 13:40 Z
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Ethan.Dicks_at_amanda.spole.gov     http://penguincentral.com/penguincentral.html
Received on Wed Jul 14 2004 - 18:28:13 BST

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