On 1/16/23 02:14, p.gebhardt--- via cctalk wrote:
> Hello list, 
>
> Yesterday, I was wondering, if there are any multiplatter disk pack 
> production tools known  to exist? 
> There are disk pack inspection and cleaning tools in the wild (also one on 
> eBay for a ridiculously high price) and occasionally, I also saw unused and 
> originally packed disk platters for sale, but these are, to my limited 
> knowledge, worthless if the production and platter alignment tools are 
> missing. 
> I remember vaguely somebody writing on this list years ago that some last 
> systems were tossed by some company in California. But disk packs were also 
> produced on the European continent and in for instance in Bulgaria(ISOT) for 
> computer disk drives in the federal republic of Germany and the Soviet Union. 
> I was just wondering about this since it is getting more and more difficult 
> to come across disk packs provided that spare unused platters arw available. 
> The (9)877 for the CDC SMD 80MB drives 9762 and OEMs seemed to have been 
> fairly wide-spread and these still show up from time to time for offer. But 
> the 300MB packs for the CDC 9766 are rare now. Older drives are close to 
> unobtainium. I never came across a five-platter pack for my CDC 854 drive and 
> i have never seen packs for my MMD 844 or my CDC BC3xx disk drive for 200MB 
> disk packs. 
> The question will rise what I wanna do with these. I have a working 9762 
> drive and some day, I would like to try to restore the other ones I have. For 
> the SMD drives, I have spare heads and alignment tools and a disk pack 
> cleaner. I don't intend to run them for hours because I don't have a clean 
> room environment that is appropriate to the specs of these drives. I just 
> love these pieces of storage technology and it would be great to at least 
> have one pack for the drives that are missing one. 
> Any thoughts from the disk experts would be greatly appreciated :)
The 844 drives date from the early 70s.  I worked for CDC on a military
project where these were brought in to replace the 821s that were bid
(yes, I know there's no information on those--they're essentially a
high-capacity unit build on an 808 chassis and unreliable as hell).  A
typical installation might have used over 100 of the units on a 4-CPU
Cyber cluster.  They worked well, unless one got a bad pack, which would
clobber the heads on a drive; using the drive on a new pack would result
in creating another head-clobbering pack.   I recall an overnight report
issued by an operator where he succeeded in trashing several packs and
multiple drives in his attempt to get something to work.  It was a
blow-by-blow report somewhat akin to the Gerard Hoffnung bricklayer story.

Can't tell you more about the mechanics of the things--I haven't seen
one of these in many many years.   They were the workhorse drive for CDC
large systems for quite some time.  We used them on the STAR-100, for
example.

All the best,
Chuck

Reply via email to