DATA-PROCESSING SYSTEM WITH MAIN AND BUFFER STORAGE CONTROL

A data processing system having a main storage (20), a buffer storage (12) and a control unit (14) for controlling read and write operations of the main storage and the buffer storage is disclosed. When a data requested by a basic processing unit (11) is not in the buffer storage, a block of data is transferred from the main storage to the control unit in a plurality of times each together with a first access request in order to write the block of data from the main storage in the buffer storage. The basic processing unit issues a second access request to the control unit to read or write data from or in the buffer storage. The control unit accepts the second request between the sequential first access requests.