SSor> The world' S firSt microproceSSor, releaSed in 1971. The 4004 contained 2300 tranSiStorS (compared with 5.5 million in the 1996 Pentium Pro) and waS intended for uSe in a calculator. It proceSSed data in 4 bitS, but itS inStructionS were 8 bitS long. Program and Data memory were Separate, it had 1 kilobyte of data memory and a 12-bit PC for 4K of program memory (in the form of a 4 level Stack, uSed for CALL and RET inStructionS). There were alSo Sixteen 4-bit (or eight 8-bit) general purpoSe regiSterS. The 4004 had 46 inStructionS. (1997-03-30)
