31 May
2016
31 May
'16
8:38 a.m.
On May 31, 2016, at 00:07, Mattis Lind <mattislind at gmail.com> wrote:
One thing to think of is that a TU58 drive does not
have optical BOT / EOT
detectors. They make use of special patterns on the tape for this. So to
format a blank tape can be a tricky operation, possibly manually
positioning the tape and then just write the nominal number of blocks and
hope the tape will be long enough.
The TU58-XA mechanism doesn't have the BOT/EOT sensors, but I believe that the tapes
still have the BOT/EOT tape perforations and the mirror behind the tape to form a 90
degree optical path. So, it should be possible to add physical BOT/EOT sensors to a
TU58-XA mechanism as part of a custom tape imager/formatter project.
The approach I'm hoping to take is different, though, and inspired by my perhaps
irrational level of distrust of the tape cartridge design: Transferring the tape to be
imaged into an audio cassette housing, and then imaging it on a hacked up transport, thus
eliminating that #*&!$*! capstan and belt mechanism from the equation.
I wonder how the TU58 tape's magnetic properties compare to any audio cassette tape
formulations? If I could find a way to create new tape belts, then it would be nice to be
able to overhaul old cartridges.
On May 31, 2016, at 03:06, Tony Duell <tony_duell at yahoo.co.uk> wrote:
Now that I have done. I started off with aluminium
alloy rpd (I think
1/2" diameter, but I can check my notes), turned it down, turned a
groove for an o-ring, drilled the centre hole (oddly for a US machine
this is 3mm, not 1/8" -- and note the motor has different diameter
spindles on the 2 ends!) drilled and tapped for the grub screw. With
a good tape I get a good, stead signal at the right speed at the output
of the read amplifier.
I like your approach for making a substitute drive wheel.
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/