Abstract: In an information processing system utilizing a virtual storage, an address translation look-aside buffer for translating a logical address into a physical address is provided to access the main storage by use of the translated physical address. The processing system has a storage control unit for controlling the operation of the address translation look-aside buffer and the main storage, which are connected with a common bus through which addresses and data are transferred on a time-division basis. The storage control unit has a bus control circuit for controlling the common bus so that addresses are transferred from the translation look-aside buffer and data is transferred to the main storage on the common bus at different times.