B&W, Ace Pilot Model 1950 magnetic Drum, front view. Scale, 0 to 3 inches, on hardware, center of photo. Solid white background. National Physical Laboratory blue ink stamped label on verso left center; "CROWN COPYRIGHT RESERVED, NATIONAL PHYSICAL LABORATORY., TEDDINGTON MIDDX.,CENTRAL PHOTOGRAPHIC SECTION, Negative No. CS/6442". "280" black pencil on verso top, center edge.
Loose strip of paper accompanying photo - "CS4813 A magnetic drum of the ACE Pilot Model with 16 read and 16 write heads, each shiftable to 16 positions, giving 256 tracks each holding 1024 bits in the contents of a delay line. Its rotation was synchronised to the delay line clocks at 1/9 of their speed, thus the sequence of storage of bits was 1, 10, 19 ..... modulo 1024.".
Identification photograph; Publicity photograph
Electronic data processing--History; Computers--History; Computer industry--History