On 29 April 1947, RAND Corporation began generating random digits with an "electronic roulette wheel", consisting of a random frequency pulse source of about 100,000 pulses per second gated once per second with a constant frequency pulse and fed into a five-bit binary counter.
The results of a long run from the RAND machine, filtered and tested, were converted into a table, which was published in 1955 in the book A Million Random Digits with 100,000 Normal Deviates.