Intel 8080

The Intel 8080 ("eighty-eighty") was the second 8-bit microprocessor designed and manufactured by Intel and was released in April 1974. It was an extended and enhanced variant of the earlier 8008 design, although without binary compatibility. The initial specified clock frequency limit was 2 MHz, and with common instructions using 4, 5, 7, 10, or 11 cycles this meant that it operated at a typical speed of a few hundred thousand instructions per second.

The 8080 required two support chips to function in most applications, the i8224 clock generator/driver and the i8228 bus controller, and it was implemented in NMOS using non-saturated enhancement mode transistors as loads, therefore demanding a +12 V and a −5 V voltage in addition to the main TTL compatible +5 V.

Although earlier microprocessors were used for calculators, cash registers, computer terminals, industrial robots, and other applications, the 8080 became one of the first really widespread microprocessors. This was partly due to its simplifying NMOS implementation (making it TTL compatible), but also to its enhanced instruction set (over the 8008) and its subsequent role as the original target CPU for CP/M, the first de facto standard personal computer operating system.