> On Oct 13, 2017, at 4:00 PM, Jack Harper via cctalk <cctalk@classiccmp.org>
> wrote:
>
>
> Greetings to the List -
>
> Does anyone have a copy of the text of the actual ISO 1863 standard that
> defines, I think, the formatting of the ancient 1/2" magnetic tapes???
>
> I am interested to understand better the format of the calculated LRC at the
> end of tape blocks, sync signals, record gaps and all the rest.
>
> I contemplate seeing if I can get an 1/2" tape drive operational with my 68K
> system by emulating the drive hardware control signals in software.
>
> ISO 1863 appears to govern that: https://webstore.iec.ch/publication/10668
Correct, if you're looking for 9-track 800 BPI (NRZI) recording. There are of
course several other possibilities: 7-track at 700, 556, or 800 BPI (NRZI),
9-track at 1600 BPI (PE) or 6250 BPI (GCR).
ISO standards are sold for actual money, so a real copy may be hard to find.
You may be better off looking for an old computer company document. The HP
document Anders mentioned might work; IBM also has several documents that are
helpful.
"Sync signals" -- that would be an interface question. ISO will not tell you
about that, it's a device detail. If you have a particular tape drive you're
working with, the spec for that drive would spell out the signals it expects
and that it generates.
paul
