8 Mar
2023
8 Mar
'23
5:20 p.m.
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