On Thu, Jul 22, 2004 at 11:38:19AM -0400, Bill Pechter wrote:
> DEC modified the SMD signals on the RM02/RM03/RM05 to make them
> slightly different from standard SMD versions and they also used
> the CDC high altitude heads to reduce crashes.
I didn't know about the high altitude heads. That's an interesting
tidbit.
> RM02/RM03 is 80mb unformatted 67 formatted. CDC sold the drive
> which could be set to many different sector sizes and sector counts
> per cyl.
>
> So the DEC was 31 or 32 (IIRC) sectors of 512 bytes per track.
> CDC topped out with 33 sectors...
A-ha! That makes perfect sense. With a bit of googling (RM02, RM03,
9762 and cylinder), the first hit is
http://www.inwap.com/pdp10/usenet/disks
In the article, among other disk sizes, the RM02/RM03 is 823 cyls, 5 heads,
32 sectors/track - 67,420,160 bytes (33 s.p.t is 69,527,040, meaning that
there must be a bit of overhead compared to the 80MB unformatted capacity).
-ethan
--
Ethan Dicks, A-130-S Current South Pole Weather at 24-Jul-2004 03:10 Z
South Pole Station
PSC 468 Box 400 Temp -83.8 F (-64.4 C) Windchill -133.1 F (-91.8 C)
APO AP 96598 Wind 18.5 kts Grid 004 Barometer 664.7 mb (11208. ft)
Ethan.Dicks_at_amanda.spole.gov http://penguincentral.com/penguincentral.html
Received on Fri Jul 23 2004 - 22:31:20 BST