9 track tapes and block sizes
J. David Bryan
jdbryan at acm.org
Mon Oct 5 00:51:34 CDT 2020
On Sunday, October 4, 2020 at 16:00, Chuck Guzis via cctalk wrote:
> A 16MB tape block is impossibly large in any case.
The HP 3000 mag tape diagnostic attempts to write a single record from BOT
to EOT, which unfortunately fails under simulation due to the 16 MB
limitation. In hindsight, it would have been better to accommodate record
lengths corresponding to the highest density and longest reel length, which
I think would need 28 bits. Four bits for metadata identifier would still
have been be good enough, and one of those should have been dedicated to
"private data" that would appear invisible to programs running under
simulation (and could be used to include information about the tape image
with the tape image).
More information about the cctech