allison wrote:
You really do need optical EOT and BOT sensors in the
loop and the
standard TU58 does not use them.
I think it should be perfectly possible to format a tape without those
sensors. Starting from the physical BOT, just make sure you write a
sufficient amount of BOT marks before writing the actual records, and
after the last record, write EOT marks until the physical EOT. The
motor current sense should be able to detect the physical EOT. If not,
I'm OK with manually sending a command to the drive when it hits EOT. I
don't think the motor has enough torque to damage the cartridge,
although I'll test that with a scratch cartridge first.
It's not only gaps, also address marks
I believe I stated that myself, if not in the message that you replied
to, then in others in this thread. However, the address marks are very
similar to the on-tape BOT and EOT marks.
First step is a full reverse engineer of the firmware.
I've done a substantial portion of that already.
My 2 cents is look at the code for the TU58 emulator
and build
hardware around that using solid state
memories.
It's been done. I'm more interested in being able to format NOS tapes
for use in an HSC50, assuming that I eventually can get my hands on an
HSC50.
Eric