(1) In electronic drum machines and sequencers, a bi-phase modulated square wave generated in the machine. This can be recorded onto tape, and when played back into the machine, will sync its signal output with the tape. Analogous to MTC and SMPTE timecodetime code, but differing in the frequencies and word lengths that various manufacturers use in their machines.
(2) The 60Hz pilot tone that motion picture cameras send to the Nagra or other sync recorder, and that controls the playback speed during transfer so that the magnetic film will sync with the workprint.