W dniu 11.11.2025 o 17:28, Phil Smith III pisze:
Hah, all good points.
As for "unstructured, informal use of tapes": back when tapes were still The Way, I'd go
to customer sites occasionally to debug some oddball problem. I had a 3480 cartridge I'd come
across with a red shell, which I'd take with because it was always easier to tell operations
"Please retrieve that RED tape you mounted..."
Until the day they put it in an STK silo. Which used a red laser to detect
tapes--and insisted the slot was empty when they asked it to retrieve it. They
wound up powering the silo down (after much discussion and permission-ing) and
physically walking in to retrieve it.
After that, I carried the red AND a standard black cartridge, and would check
whether they had a silo...
AFAIK the 3495 tape library (not 3494) used laser to distinguish CST aka
3480 vs ECCST aka 3490E carts.
Hint: CST cart is all black. ECCST is half black, half-white.
Was it effective? I have no experience, but I don't think so.
However later they introduced "seventh letter" on external label
(sticker) - 1, E, J, K. Then two letters: JA, JB, JC...
Note: the "media type" letters became informal de-facto standard across
all tape world, even non-mainframe. It was used by STK, LTO, Sony, etc.
--
Radoslaw Skorupka
Lodz, Poland
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