His Nibbler implements a 4-bit CPU using 7400 logic chips. Because he’s come up with the architecture himself he’s taking a lot of steps to check all of his work before committing to a PCB.

In the early days of microprocessors, bit slice processors ... which included the Am2901 4-bit slice ALU. See ALU. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction requires permission.

But in 1990, the U.S. Patent Office gave that recognition to Hyatt. Intel's 4004 (4-bit) microprocessor was the on the market, however, and in 1974 they added the 8080 (8-bit), sixteen times more ...

April 1972: Intel introduces the 8008, the first 8-bit microprocessor. Jonathan A. Titus designs the Mark-8, "Your Personal Minicomputer," according to the July, 1974 cover of Radio-Electronics.