On 3/8/23 06:19, Paul Koning wrote:
> I wouldn't exclude those, certainly not if they are relevant to the evolution > of the technology. Are X1 tapes (and Eliott tapes if they are the same > format, which I don't know) in some way anticipating LINCtape and DECtape? > Are they an independent invention of roughly the same concept? For that > matter, would you exclude DECtape on the grounds that it's single vendor? I > hope not. For that matter, I suspect the Uniservo I format is specific to > Univac, yet you can't very well exclude that from a history of magnetic tape > data recording. I view "captive formats" such as DECtape to be evolutionary dead ends. Consider, for example, the Datamatic 1000 tapes--I doubt that more than a handful of people here have ever heard of the system. A captive format. Or the early Uniservo metal tapes? Or the tapes used in the IBM 2321 Data Cell or 3850 MSS? Captive formats and evolutionary dead-ends. How about the stuff that never made it out of the lab? Such as the CDC SCROLL? I suspect that I may be one of few who even have heard of the beast--yet it was included in our forward-looking boilerplate in STAR proposals. How about the 9 track 1/2" 3200 fci tapes? Not mentioned yet. Quarter-inch cartridge tapes were quite varied. Although looking the same at first glance, there were significant differences. Consider the Alphamat...Zetamat 3M series of quarter inch tapes. (e.g. DC600HC). No optical sensing of BOT/EOT/media type holes--all done with preformatting. Those were popular with ADIC crowd--I have a couple of those drives in the eventual case that someone digs a tape up from the trash heap of history. How about the adapters that allowed use of VHS cassette equipment for backup? All dead-ends. Before disks were affordable, or even available, half-inch tape was used as primary storage. Consider the 7090 IBSYS shops--all tape operations. --Chuck
