I hate to throw a spanner in the works but no one has mentioned U-Matic
tapes. Normally used for video recording the early CD audio and CD-Rom
industry encoded the digital image on to U-Matic tapes which were then
used to drive the laser for writing to the CD Master.
On 3/8/2023 11:42 AM, Paul Koning via cctalk wrote:
On Mar 8, 2023, at 12:20 PM, Chuck Guzis via cctalk <cctalk@classiccmp.org>
wrote:
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?
I would disagree with that blanket assertion, for two reasons. One is that something
isn't an "evolutionary dead end" only if nothing later was inspired by it and
constructed, to some extent, along similar lines. In that sense the Uniservo tapes are
not at all a dead end; instead, they are the ancestor of all later tapes. Properties
like metal vs. plastic media and 6 tracks vs. 7 or 9 or more are details.
Second, I would consider a format to be significant if it had a major market
presence and major place in the technology space. In that sense, DECtape I
clearly belongs -- being either the primary or a significant secondary storage
device for a decade or two of some of the world's most successful computer
lines.
Similarly, is DLT a "dead end"? It was captive to some extent until it spread
out, but then LTO replaced it. On the other hand, isn't LTO clearly an evolutionary
variant of DLT?
I'd agree that there are a number of other formats that were neither significant players
nor a significant influence on later work. The CDC 14-track tapes would fit that
description, and the Eliot or X1 10-track tapes most likely as well. But I would argue
that "if it wasn't an industry or ISO standard it doesn't count" is too
restrictive a view, especially if you aim to produce a history of the technology space.
paul
