tl;dr: The Zilog Z80, launched in July 1976 by ex-Intel engineer Federico Faggin, evolved from the Datapoint 2200-derived 8008 and 8080 lineage, adding index registers, shadow register banks, new instructions, and a simpler single-supply bus design while remaining binary compatible with the 8080. It became a dominant 8-bit processor in early PCs, home computers, and embedded systems, spawning clones like the Game Boy's Sharp LR35902, before Zilog finally discontinued the original in June 2024. The article also recounts how Exxon's ownership stake contributed to IBM choosing Intel's 8088 for the PC.