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- Newsgroups: comp.sys.hp
- Path: sparky!uunet!cs.utexas.edu!csc.ti.com!tilde.csc.ti.com!m2.dseg.ti.com!ernest!cmptrc!jwoods
- From: jwoods@cmptrc.lonestar.org (Jeff Woods)
- Subject: Re: HP7933, HP7935, HP7935+"Cache Memory"
- Message-ID: <BxnDnC.Msu@cmptrc.lonestar.org>
- Date: Fri, 13 Nov 1992 09:14:00 GMT
- References: <BxK6uq.I2v@lysator.liu.se>
- Organization: CompuTrac Inc., Richardson TX
- Lines: 30
-
- In article <BxK6uq.I2v@lysator.liu.se> root@lysator.liu.se (Peter Eriksson) writes:
- |What is the difference between the HP 7933, the HP7935 and
- |a HP7935 with a sticker "CACHE Memory"?
-
- The 7933 disk drive is a 404 Mb drive with a removable disc pack which HP
- decided during testing (apparently) was unreliable unless the pack was never
- removed, so they disabled the user-removal of the pack feature and sold it
- anyway. The 7935 is a 7933 which has the drive opening mechanism installed
- and HP charged more for it. I think maintenance was more expensive also.
- They are identical in every other way. [And 7933 drives are user openable
- (but not supported in that way) if you pay attention to a CE working on one
- or are good with mechanical and lock puzzles.]
-
- The Cache Memory sticker indicates that a cached controller is installed
- in the drive. The standard 7933 & 7935 drives transferred data directly from
- disk to the HPIB bus without any buffering, hence the slower rotation speed
- of the drive: to match the HPIB bus speed. Both the 7933 and 7935 support
- cache memory. The cache memory was an option introduced years after the
- drives were and was available as an option on new drives after that and as
- an upgrade option for older drives. Therefore, you may find drives with the
- upgrade installed without the sticker applied and (less likely) vice versa.
-
- It's been a few years since we got rid of our 7933s, but I'm reasonably
- certain of my facts still.
-
- Sorry, I've never used them on the 9000. We used them on the HP3000 only.
- --
- jwoods@cmptrc.lonestar.org (Jeff Woods at CompuTrac, Inc.)
- stdinfo: "My opinions are my own."
- "You don't need a programmer so much as you need a exorcist." - A. Chambers
-