On 3/7/23 17:04, Zane Healy via cctalk wrote: > I’m working on a project, and I need to know the age of various tape formats. > For example when were 6250bpi 700’ 9-Track tapes or DC600A cartridges > introduced? Is there any good resource online that documents this? > Wikipedia is of some help, but the older you go, the spottier it is
Strictly speaking out of an orifice, I'd suggest that 9 track tapes in NRZI and PE first came around with the IBM 2400 series tapes, GCR with the 3400. Prior to the S/360, tape drives were largely 7 track and used NRZI in 200, 556 and 800 bpi densities (IBM 700 series drives). Of course, there are many outliers. As far as QIC-24 (DC600A), the applicable standard dates from 1983. https://www.qic.org/html/qicstan.html FWIW, --Chuck
