The IBM 1620 that I programmed in 1965 had 20,000 binary-coded digits. Each digit was 6 bits -- 4 numeric bits, a check bit, and a flag bit to indicate the high

The IBM 1620 that I programmed in 1965 had 20,000 binary-coded digits. Each digit was 6 bits -- 4 numeric bits, a check bit, and a flag bit to indicate the high order digit of variable-length decimal-encoded numbers. Of course there wasn't enough RAM ... we used phases, overlays, and other techniques to juggle the code. Later I helped build the ARPANET at UCLA ... that was 1969-70. We were still pioneers.