FIELD: digital signal processing, in particular, using INRZI modulation. SUBSTANCE: pre-coders provide preliminary express encoding using through integration of subsequent bits, which are used for production of each channel word. Two pre-encoders generate n-1 parallel bit channel words, so that channel word frequency is less than frequency of system synchronization pulses used for INRZI modulation by factor of n+1. This results in additional time within each channel word interval for making decision about selection of writing channel word from set of channel words generated by two pre-encoders. EFFECT: elimination of read/write buffer memory due to parallel bit-wise preliminary encoding for generation of channel words selected for writing operation. 33 cl, 33 dwg
