 It was developed by Federico Faggin, using his silicon-gate MOS technology, along with Intel engineers Marcian Hoff and Stan Mazor, and Busicom engineer Masatoshi Shima.It was followed by the 4-bit Intel 4040, the 8-bit Intel 8008, and the 8-bit Intel 8080.All of these processors required several external chips to implement a working system, including memory and peripheral interface chips.