DUPLEX COMPUTER SYSTEM

PURPOSE:To make the processing of both computers coincident in the computer constituted in a double system by permitting the access to the same table by a program to only one program at any time. CONSTITUTION:In a resources releasing waiting request retrieving part 37, a double system control device 7 completes the synchronization, searches the synchronizing reservation request of a program P2' which waits for the releasing of the resources and instructs the processing to a resources reservation processing part 38. The resources reservation processing part 38 executes the reservation of a table T1 and reports the permitting signal through permitting sending parts A33 and B34 to both computers. This is received, the program P2' of both computers 3 and 4 restarts the execution, and the information is respectively read from the table T1 of the own computers 3 and 4. The information read at such a time is the information where a program P3 is written in both computers, and therefore, the information is coincident in both the computers 3 and 4. Thus, the processing of both the computers can be always coincident.