Gse, Inc.

Peter Roggendorf

A method of and apparatus for editing half-inch tape used for home recording of video material applies pulse-width modulation to prerecorded synchronizing pulses in predetermined time intervals. The interval is started with an eleven-bit header that is compatible with that of a commercially available system known as the VASS system. Time blocks are then encoded by pulse-width modulation with information identifying the particular recording session and the number of elapsed seconds minutes and hours since the beginning of the session. A check code completes the modulation during the interval for television systems such as and SECAM that are adapted for fifty-Hz operation. For systems such as NTSC that operate at sixty Hertz, a ten-bit dummy code is added to complete the two-second interval. The code is entered without writing over the leading edge of the prerecorded synchronizing pulse, allowing the timing of those pulses to continue without interruption. Using this system, an editor can locate any desired interval and can then locate an individual frame within that interval by counting synchronizing pulses. The apparatus of the invention inserts and detects the header, inserts and detects the address code, inserts time signals in sequence, and detects a selected time interval and frame within that interval. An electronic circuit processes signals derived from the tape for input to a microprocessor which controls displays, insertion of codes, and advancing to a chosen edit location.

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Munich, Georgia

Peter Roggendorf