The magnetic-drum store of the computer Pegasus

摘要

The paper describes the mechanical detail, logical arrangement and electronic design of a fully-packaged drum storage system. The mechanical design of the drum has been based on current extremeprecision machine-tool practice, for reliability. Methods of track selection are electronic on both writing and reading, taking the form of electronic cross-bar switches. On the reading side, the switch is formed by an array of balanced germanium-diode gates which are interposed directly after the magnetic heads, prior to amplification. The system reliability proved to be very satisfactory in the light of the first 1500 hours' operating experience.