Shuffling Machine - After World War II

After World War II

After World War II, engineers tried to generate random sequences using electrical devices. Noise sources (like a hot cathode gas discharge tube or a resistor) would typically be sent through filters and amplifiers to output one or several random streams. Such device is described in a 1940 patent by Newby et al.. Though most patented machines continued to be based on old mechanical designs that did not provide as much randomness as noise sources but were more practical. According to the patents filled during the 1950s and 1960s, designers created simple devices where a basic shuffling operation was repeated several times (by feeding the output deck back into the machine) instead of having one complex pass implying many tricky mechanical operations ending up with a poor shuffling and lower reliability. Some of them tried to reproduce what was manually done during a riffle shuffling with cards interleaving each others. Cards picking using rollers in contact with the top or bottom of the deck were still heavily used at that time.