ACCESS CONTROL SYSTEM OF INDEXED SEQUENTIAL FILE

PURPOSE:To make the operation of indication to a former position unnecessary and to improve the processing efficiency by restoring the former sequential access call point to restart sequential access simultaneously with the end of an additional control when sequential access call is interrupted to perform the additional control. CONSTITUTION:A key value of a record in a file device 3 accessed by an access position control part 7 is set to a pointer 11 of an indexed sequential file access control part 2 of a processor 1. Contents of the pointer 11 are increased by +1 by a computing element 12 to read the continuous key value to a call control part 8 unless an instruction which designates a discontinuous key position is issued. When a command decoding part 6 detects an addition command, sequential access of the control part 7 is interrupted by an addition control part 9. The next access position of sequential access of the pointed 11 and its related information are saved in a work area 14 of a main memory 13, and a key value of an additional position is set to the pointer 11, and the saved key value is restored in the pointer 11 to restart access control when the addition processing is terminated.