JPS6449173A - Decoder in data storage system - Google Patents

Abstract

PURPOSE:To obtain a decoder capable of decoding an always correct binary data string by demodulating a binary coded string read out from a storage device at the same timing as encoding. CONSTITUTION:A synchronizing bit pattern for synchronously controlling a variable frequency oscillator 16 is inserted into the leading gap area of a binary data string to be encoded by an encoder 12 in accordance with a prescribed encoding system, encoded together with the binary data and stored. The generation of a clock pulse 22 from a decoder 21 is started by the synchronizing bit pattern stored in the gap area to be initially obtained at the time of reading out the binary encoded string. Consequently, the clock pulse can be generated at the same timing as modulation starting timing based upon the encoder 12 and the unmodulated binary data string can be surely reproduced. Even when a magnetic disk unitedly including the encoder and the decoder is connected under any control device, a correct binary data string can be decoded.