Category
page 14-bit microprocessors
Intel 4004
4-bit central processing unit; one of the earliest processors made by Intel, made on November 15, 1971
Intel 4040
4-bit microprocessor introduced in 1974 by Intel
Texas Instruments TMS1000
electronic microcontroller

HP Saturn
family of 4-bit datapath, nibble serial, CISC, calculator, pocket computer and printer general purpose processors with 20-bit addressing capabilities and 64-bit general purpose registers