> The 64 teeth for Sega I thought was well thought out since in
> quadrature that
> gives 256 positions in one rotation, allowing one, in software, to use
> absolute
> positions associated with absolute values.
>
> I have no idea where Atari got 72...
>
In some of the development stuff Travis and I got from Atari there was a
bunch of Tempest encoder disks with all sorts of different numbers of
teeth cut into them. Dunno what they were for. Maybe they just tried
different stuff to see what "felt" best.
There was also a Tempest control panel (w/out overlay) that was setup
for a trackball. Haven't a clue what that was for. Maybe a Quantum
conversion kit for Tempest?
-Clay
