CONTROLLING SYSTEM FOR INPUT OUTPUT PROCESSING

PURPOSE:To simplify the discrimination of address renewal timing by informing the status when the last position of the same cylinder and the same track has been reached during access to a program requesting its access. CONSTITUTION:When addresses in a parameter list 27 are transferred to an input output (I/O) processing routine 21 by a program to be requested, information on the existence of a local post moving request is set up to a local post request indicating flag 31 and the last selector No. on one track is set up on a counter area. When the contents of a renewal sector address area 35 coincides with that of a counter area 32 in the I/O processing routine 21, the local post request indicating flag 31 is set up on a local post flag 37 in a block 25, the processing end is informed to the program 20 to be requested and the information as to various status is stored in a data control block 26.