History of RAND's Random Digits: Summary

Abstract

Experimental probability problems, in connection with a diversity of applications, led to a desire for a large supply of random digits, of sufficiently high quality so that the user wouldn't have to question whether they were good enough for his particular application in the case of every different application. A random frequency pulse source was gated by a constant frequency pulse, about once a second, providing on the average about 100,000 pulses in one second. Pulse standardization circuits passed the pulses to a five place binary counter, so that in principle the machine is like a roulette wheel with 32 positions, making on the average about 3000 revolutions on each turn. A binary to decimal conversion was used, throwing away 12 of the 32 positions, and the resulting random digit was fed to an I. B. M. punch, yielding punched card tables of random digits. A detailed analysis of the randomness to be expected from such a machine was made by the designers and indicated that the machine should yield very high quality output. (Author)