Tape dumping programs for Unix/Linux...

From: Frank McConnell <fmc_at_reanimators.org>
Date: Thu May 2 11:23:33 2002

"Douglas H. Quebbeman" <dquebbeman_at_acm.org> wrote:
> The emulator community is vigorously using a tape image container
> format known as TAP for precisely this purpose.
>
> Each record from tape is written to file prefixed *and* suffixed
> by a four-byte record length in little-endian format. A zero-
> length record is represented by a 4-byte value of zero; although
> intuition might call for 8-bytes (a prefix & suffix with nothing
> in between), this is not the case. The convention appears to come
> directly from FORTRAN 77's handling of unformatted sequential files.
>
> And EOF is represented by two consecutive zero-length records.

Thanks, I've been curious about this spec for a while and had little
luck turning up a concise description of the format.

One question, if I want to write multiple consecutive EOFs (I'm
thinking of classic HP3000 MPE :STORE format tapes here) do I write
two zero-length records for each, or do I "compress out" the
zero-length records in the middle? Say I want to write two EOFs,
do I write {0,0,0,0}, {0,0,0,0}, {0,0,0,0}, {0,0,0,0} or
{0,0,0,0}, {0,0,0,0}, {0,0,0,0}? I'm hoping it's the former.

-Frank McConnell
Received on Thu May 02 2002 - 11:23:33 BST