Replay of digital data from disc system - using modified frequency modulation technique with ROM-based decoding system

摘要

The replay of digital data from a disc storage system based upon a modified frequency modulated technique, uses r.o.m.s. to generate decoded digital values. The analogue outputs of the disc are digitised by a 'D' type flip-flop to generate a data stream to a shift register. The latters outputs are entered in a counter to define the number of bits of information in a serial transmission. Read only memory stages are accessed at specific intervals to provide data status signals. The conversion process is controlled by a clock generator to provide the decoded binary values.