Interesting. One note, the TTL was a very successful family of integrated logic devices (the 7400 series introduced by Texas Instruments), but it wasn't the fir

Interesting. One note, the TTL was a very successful family of integrated logic devices (the 7400 series introduced by Texas Instruments), but it wasn't the first. The earliest was RTL (resistor-transistor logic). Many years ago I built an RTL circuit that played the game of Nim [1] on up to four heaps and 15 counters per heap, using perfect strategy. Other logic families were ECL, IIL, and my favorite for simple projects CMOS (very low power that could be supplied at a range of voltages). [1] http://www.math.cornell.edu/~mec/2003-2004/graphtheory/nim/howtoplaynim.html http://www.math.cornell.edu/~mec/2003-2004/graphtheory/nim/h...