22 Jul
2004
22 Jul
'04
11:43 a.m.
On Tue, Jul 13, 2004 at 05:32:21PM +0800, Wai-Sun Chia 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.
It's all true.
A CDC 9762 _is_ an SMD drive. DEC made some changes to the cards inside
the 9762, put it on a DEC pedestal and filled the bottom with a couple of
cubic feet of DEC electronics. Working for a small 3rd-party support
company years ago (c. 1988), I tried to "restore" an RM02 back into an
SMD device (since my boss had Unibus SMD controllers and no MASSBUS
machines), but we eventually gave up. It's not as simple as unplugging
the equipment in the bottom of the RM02/RM03 and plugging the 62 pin/26 pin
cables into a real SMD controller.
The capacities you list are also correct - the original 9762 gives you 80MB
per pack, and the same pack in a DEC RM02/RM03 gives 67MB. I do not happen
to know if it's just a difference in the number of reserved tracks for
spares, or if there is an low-level format difference.
-ethan
--
Ethan Dicks, A-130-S Current South Pole Weather at 22-Jul-2004 23:30 Z
South Pole Station
PSC 468 Box 400 Temp -95 F (-70.5 C) Windchill -135.4 F (-93 C)
APO AP 96598 Wind 9.6 kts Grid 034 Barometer 664.5 mb (11217 ft)
Ethan.Dicks(a)amanda.spole.gov http://penguincentral.com/penguincentral.html