What are the differences between a 7404 hex inverter and a MC789 hex inverter and a uL9109 hex inverter and a 10H189 hex inverter?

Answer 1

The 74xx series of integrated circuits use TTL technology. (Transistor Transistor Logic). They work on 5v power supply, and draw a larger current. The MC type chips are CMOS. (Complementary Metal Oxide Silicon) they work off a more varied voltage range, 5v - 18v and draw less current than TTL. Other different numbers will relate to the package design and speed of operation.