23 Jul
2010
23 Jul
'10
11:28 a.m.
IRIC the Tekky 405x series didn't use any of
the standard encodings,
though. They had a 2 coil head that read/wrote 2 tracks at the same time.
A pulse on one track was a '0' bit,a pusle on the other track was a '1'.
Whether simultaneous pulses on both tracks were used as some kind of
marker I don;t know, many otehr similar systems did use that.
It was indeed. Pulse on one track = 1, pulse on other track = 0, pulse
on both tracks = marker. The pulses on each track were alternately
positive- and negative-going to minimise the dc component.
I have the spec somewhere. Probably in one of my Tek service manuals.
How detailed a spec? Is there enough to understand the cotnents of a tape
at the file level?
-tony