The Intel 4004 Microprocessor Turns 44

mcpublic writes: Today is the 44th anniversary of the Intel 4004, the pioneering 4-bit microprocessor that powered the first electronic taxi meters. According to the unaffiliated (and newly renamed) Intel 4004 45th Anniversary Project web site, they have just re-created the complete set of VLSI mask artwork for the 4004 using scalable vector graphics, and updated their Busicom 141-PF calculator replica aimed at collectors and hobbyists. Included is some interesting historical perspective: Back in the early 1970s, there was no electrical CAD software, design-rule checkers were people, and VLSI lithographic masks were hand-crafted on giant light tables by unsung "rubylith cutters."

Comments

Rubylith was state of the art!

[Terje Mathisen]

My father spent months at his home-made light table back around 1965 cutting traces in rubylith film in order to create the offset masks for orienteering maps.

He needed one such mask for each color in the finished map, any mistakes had to be fixed with small amounts of red lacquer which then had to dry completely before it could be recut.

The big advantage for VLSI vs a map was that most lines were straight so you didn't need to trace curved lines like you do for the contours on a map.

Terje