Abstract: In a signal processing unit for writing/reading data on/from a disk-shaped recording medium of a disk apparatus, all of a data separator, a code decoder circuit, a code encoder and a write compensation circuit are constructed on a one-chip integrated circuit. The data separator separates a synchronization clock from a code data reproduced from the disk. The code decoder circuit produces decoded data from the synchronization clock as the output from the data separator, and synchronized code data. The code encoder encodes data supplied from a host computer or a disk controller into code data. The write compensation circuit compensates for a peak shift with respect to write code data. This integrated circuit is fabricated by a Bipolar-CMOS process by which a bipolar transistor and a CMOS transistor are mixed with each other thereon.

Abstract: In a signal processing unit for writing/reading data on/from a disk-shaped recording medium of a disk apparatus, all of a data separator, a code decoder circuit, a code encoder and a write compensation circuit are constructed on a one-chip integrated circuit. The data separator separates a synchronization clock from a code data reproduced from the disk. The code decoder circuit produces decoded data from the synchronization clock as the output from the data separator, and synchronized code data. The code encoder encodes data supplied from a host computer or a disk controller into code data. The write compensation circuit compensates for a peak shift with respect to write code data. This integrated circuit is fabricated by a Bipolar-CMOS process by which a bipolar transistor and a CMOS transistor are mixed with each other thereon.

Abstract: In a signal processing unit for writing/reading data on/from a disk-shaped recording medium of a disk apparatus, all of a data separator, a code decoder circuit, a code encoder and a write compensation circuit are constructed on a one-chip integrated circuit. The data separator separates a synchronization clock from a code data reproduced from the disk. The code decoder circuit produces decoded data from the synchronization clock as the output from the data separator, and synchronized code data. The code encoder encodes data supplied from a host computer or a disk controller into code data. The write compensation circuit compensates for a peak shift with respect to write code data. This integrated circuit is fabricated by a Bipolar-CMOS process by which a bipolar transistor and a CMOS transistor are mixed with each other thereon.

Abstract: When data are memorized in a 2-7 RLL code on a disc shaped memorizing medium using a sector format, as an address mark in each sector a 2-7 illegal pattern is used; a 1-byte data "8B" in an NRZ signal is converted into a 2-7 RLL code, and further it is modified into the 2-7 illegal pattern.A disc controller in a disc memory inserts the 1-byte data "8B" into a specified position in an NRZ signal and transmits it to an encoder/decoder. In the encoder, the 1-byte data "8B" in an NRZ signal is detected, and a 2-7 illegal pattern is formed by reversing a specified bit of a 2-7 RLL code formed by converting the 1-byte data "8B", and the illegal pattern is sent to the read/write amplifier.

Abstract: A disk drive system includes a magnetic disk apparatus which accurately positions read/write heads for reading data from and writing data on tracks on the data surface of a rotary disk on a predetermined track on the disk on the basis of servo data written in the servo area formed on the data surface, and a disk controller which controls the mode of operation of the disk apparatus. Index signals respectively indicating the start and end of the servo area are generated on the basis of the result of detection of the angular phase of the disk. The mode of operation of the magnetic disk apparatus is determined on the basis of a write control signal provided by the disk controller. The index signals respectively indicating the start and end of the servo area are sent to the disk controller when the mode of operation is track format write mode, while the index signal indicating the end of the servo area is sent to the disk controller when the mode of operation is other than the track format write mode.

Abstract: An input/output control device stores variable-length data in a memory device at a high storage efficiency and without reducing the speed of data processing. The data stored in a memory are read out in the form of data of a fixed word length and then processed, the data having been processed are stored in another memory in the form of data of the fixed word length. The data stored in another memory are subjected to data organization to be outputted in the form of data of a given word length. Each of the memories is divided into a plurality of regions, and each region stores therein data of the same word length, respectively.