The Intel 8253 and 8254 are programmable interval timers (PITs), which perform timing and counting functions using three 16-bit counters.
Intel C8253
The Intel 8080 ("eighty-eighty") is the second 8-bit microprocessor designed and manufactured by Intel. It first appeared in April 1974 and is an extended and enhanced variant of the earlier 8008 design, although without binary compatibility. The initial specified clock rate or frequency limit was 2 MHz, with common instructions using 4, 5, 7, 10, or 11 cycles. As a result, the processor is able to execute several hundred thousand instructions per second. Two faster variants, the 8080A-1 and 8080A-2, became available later with clock frequency limits of 3.125 MHz and 2.63 MHz respectively.
The 8080 needs two support chips to function in most applications: the i8224 clock generator/driver and the i8228 bus controller. It is implemented in N-type metal–oxide–semiconductor logic (NMOS) using non-saturated enhancement mode transistors as loads thus demanding a +12 V and a −5 V voltage in addition to the main transistor–transistor logic (TTL) compatible +5 V.
Closed and open Intel 8080 processor
AMD Am9080
CEMI MCY7880 (Poland)
Kvazar Kiev K580IK80 (Soviet Union)