Mini-disc recorder-player with high speed copying - provides magneto=optic recording with error correction and copy protection

摘要

The mini-disc system has an intermittent record mode in which input signals are digitised and compressed to 1/5 of their volume, and error detection codes are added. In copy mode, a switch is set to receive an input data stream from a replay signal processor which delivers an error corrected data stream. The controlling microprocessor switches the mode to continuous output at the disc data rate so that no gaps in the stream are present. The signal passes through an ECC encoder (5), a modulator (6) for EFM (e.g. from eight to fourteen) modulation and to the magnetic record head (8). A copy protection code detector in the replay circuit prevents this transfer when copy protect is set.