[sdiy] Embedded micros

[Steve Ridley]

> Phillips used this method in the 1930s for film and audio recording.
> Some Dutch radio stations seemed to have used this system at the time.
> I once heard a tape copy of one of these optical recordings.
> The quality was really amazing for something recorded 70 years ago, far
> better than 78 rpm records.

You're may be referring to the Phillips Miller (sp?) machines.
Radio Luxembourg had some, which were "rescued" during the early
part of WW2 before the Germans got to them and installed in the 
BBC studios at Maida Vale, London.  It used a sapphire stylus to etch
a track onto the film, and it was read optically.  Two Dutch diamond 
cutters who had also fled before the Germans had a room in the 
ex convent next door where they came every week to regrind the styli.
I think this information is accurate - I heard it from an elderly woman
who used to work there.

There were also some optical organs using patterns cut into disks,
but they were never as successful as the Hammond tonewheels or
Compton electrostatic system.  (Comptons also came up with the
rotating speaker idea several years before Leslie, but they didn't 
bother patenting it because they thought it would never catch on...)

There was also some interesting work on optical waveform generation
done by Daphne Oram.



Steve Ridley