System WHZ  (1966)
Strand

Unreliable, but was 'the world's first stage lighting control to record dimmer positions instantly by magnetic means, access for playback or modification being immediate also'. 
Thorn's Q File was launched 4 months later, and worked reliably. 
(from Sixty Years of Light Work by Fred Bentham)

See also:

• Q-File (1966 - ?)

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