GB1189025A - Digital Data Storage System - Google Patents

Abstract

1,189,025. Data storage. INTERNATIONAL BUSINESS MACHINES CORP. 24 July, 1968 [16 Aug., 1967], No. 35226/68. Heading G4C. In a digital data storage system having two cyclic stores 60, 70 of different cycle time, data is transferred from a location of the store of shorter cycle time 70 to a buffer store 80a in response to an indication from address identifying means of concurrent accessibility of likenumbered locations in the two cyclic stores, for subsequent transfer to the other cyclic store 60. Each cyclic store 60, 70 has two magnetostrictive delay lines, 60a, 60b or 70a, 70b, operating in parallel, and recirculating via registers used for entry and exit of data. Data can be transferred in time-division-multiplex manner, between a computer (not shown) connected to line 1, and I/O devices 2a, 2b (via cyclic store 60), 3a, 3b (via cyclic stores 60, 70 in turn), each cyclic store having an address for each associated I/O device. Unit 62, associated with cyclic store 60, contains a clock-driven character counter driving an address counter. Equality between this address counter and a similar counter in unit 72 associated with cyclic store 70, detected at 85 permits data from cyclic store 70 to be entered into register 80a and the I/O device address to be entered into a register 80b. Agreement between the latter address and the address counter in 62, detected at 86 permits the data at 80a to be passed to the cyclic store 60. Comparison as above at 85 permits data from cyclic store 60 and a corresponding device address to be entered in registers 90a, 90b respectively, the data being passed to cyclic store 70 on equality between the address in 90b and the counter in unit 72, detected at 96. Transfer is also dependent on it being required, control bits being present in the cyclic stores 60, 70 and being transferred between the cyclic stores using the above facilities, for this purpose. Registers 80c, 90c for control bits are also provided. Drums and discs are mentioned as possible cyclic stores.