JPS6427078A - Disk controller - Google Patents

Abstract

PURPOSE:To speed up a magneto-optical storage by providing a data recording area and an alternate area on one and the same track and executing an erasing and a writing in the same cycle. CONSTITUTION:When a light command is sent from a host computer CPT 21 to a controller 20, a CPU 26 analyzes the command according to a program in a ROM 27, decides the writing area of data and transfers writing data to a buffer 23. When the data is written to sectors 2-4 of a data area 11 on the track, in a first cycle, the sectors 2-4 are erased, and sectors 7-10 of an alternate area 12 are read. Reading data are sent from a magneto-optical recorder 30 to the buffer 23. In a second cycle, the data are written to the sectors 2-4 by an inverse route and the sectors 7 and 8 are erased. In a third cycle, the sectors 2-4 are read, and when errors are generated, they are written to the area 12. In a fourth cycle, the sector 7 is read, and when the errors are generated, the writing and reading are repeated to the area 12.