Digital Storage of Statistical Data

In the field of nuclear instrumentation, there is need for an economical instrument capable of storing data compactly in digital form. This paper delcribes a magnetic tape recorder which can store binary numbers from one to a maximum of eleven digits in parallel on a continuously rotating loop of tape. The tape is operated at a constant speed of 30 inches per second and a packing density of 667 bits/inch/track and can be used in loops of two to 1000 feet. For these operating conditions, the average storage access time for random inputs is 25 μsec. Stored data are read back from the tape into a core-memory matrix at a 20-kc rate. The operational reliability for the recording and reading processes has been found to vary between 4 and 14 parts/ million. Higher reliability may be obtained by using the tape at lower packing densities.