The Magnetic Tape System of the Kyoto University Digital Computer KDC-I

Abstract

This paper describes the details of the magnetic tape system of the Kyoto University Digital Computer KDC-I with emphasis on the design features and problems. The system was developed and built in collaboration with Hitachi, Ltd., and was attached to the main part of the computer in October 1960. The tape is used only as a secondary memory and not as an input/output medium at present. The tape system includes magnetic tape handlers and a magnetic tape control unit which contains a high speed magnetic core memory. The main features of the tape system are :-concurrent operations of the tape and of the main part of the computer, a new block number system which was named a variable block number system, an instruction system which enables a simple treatment of the drop-out problem of magnetic tape, noise suppression and the correction of time displacement error by using the KDC-I basic logic circuits, and so on. In spite of difficulties at the time of the design of the system, the completed tape system satisfies the required functions and is utilized almost daily at the Kyoto University Computation Center.