Abstract: A system and method for generating a unique sync pattern that may be appended to a selected data sector of a disk storage system. The data to be stored in the disk storage system is encoded in accordance with a desired fixed rate run-length limited code, such as a 2,7 code. The unique sync pattern is generated by first encoding a prescribed data word in accordance with the desired code. At least one bit of the encoded prescribed data word is then changed in a manner such that the changed encoded word still complies with the coding rules of the desired code, yet the resulting bit pattern does not represent any valid sequence of data in accordance with the desired code. Hence, the changed encoded word may be readily distinguished from data, thereby providing the synchronization function, while still being handled and processed by the same encoding/decoding circuitry as is employed to handle and process the data.

Abstract: Disclosed is a data detection system and method for accurately detecting data transition marks recorded on a recording surface. A data transition pulse, generated by a data head as recorded data transition marks pass thereby, is presented to consecutive delay circuits in order to generate first and second delay pulses. The second delay pulse and the data transition pulse are subtracted from the first delay pulse, thereby creating a narrow output pulse that indicates the occurrence of a data transition. This narrow output pulse is used to toggle a flip-flop or equivalent logic circuit, the flip-flop output thereby representing a recreation of the data as recorded on the recording surface. The system is best suited for use with an optical storage system wherein data transitions are recorded on an optical disk as spots of substantially uniform size, although the detection system does not require that the spots be uniform size.