METHOD AND DEVICE FOR PROVIDING PROGRAMMED OPERATION OF DIRECT ACCESS MEMORY SUBSYSTEM

摘要

PURPOSE: To shorten a response time and to improve availability of data by storing various disk files of a mirror type in each of plural disk drives in a position deviated by a prescribed rotary angle. CONSTITUTION: N pieces of mirror type data files having the same data contents are written in each disk of N pieces of disk drives A1 -AN shifting individual phase relation by 360 degrees/N. A position of each spindle for various disk drives of a cluster is given by a programming signal on a control conductor 63 for driving individual disk. A delay network 62 for disk drive Ai is set so as to cause delay of 360 degrees×i/N for generating an index signal for drive Ai . Thereby, when a data access command is generated, it accesses to the closest file. Therefore, a response time is shortened, while availability of data is improved.