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
