The Busicom 141-PF, released in March 1971, was a desktop printing calculator that holds a special place in computing history as the first commercial product to use a microprocessor—the Intel 4004. This collaboration between Japanese calculator manufacturer Busicom and Intel marked the birth of the microprocessor era, proving that complex computing functions could be integrated onto a single chip.
The 141-PF was developed by Nippon Calculating Machine Corporation (Busicom), a Japanese company specializing in electronic calculators. Busicom engineer Masatoshi Shima designed the logic, while Intel was contracted to produce the chipset. Intel engineers Ted Hoff, Federico Faggin, and Stanley Mazor created the MCS-4 family, including the 4004 CPU. Hoff's idea to consolidate functions into a programmable microprocessor revolutionized the project.
In 1969, Busicom approached Intel to design 12 custom chips for their advanced printing calculator. Hoff proposed a single general-purpose CPU instead, reducing to four chips. Development took 9 months, with Faggin leading silicon implementation. The 141-PF launched in Japan in March 1971 (international later). Busicom held exclusive rights initially, but Intel bought them back for $60,000 in 1971, allowing broader 4004 sales. About 100,000 units were produced before Busicom's 1974 bankruptcy.
The 141-PF used the Intel 4004 4-bit microprocessor. Key features included:
The MCS-4 chipset enabled compact, low-cost design compared to discrete logic calculators.
The 141-PF's "software" was firmware in ROM chips, handling calculator functions like addition, subtraction, multiplication, division, percentages, and memory registers. It supported floating-point decimals and printed results with red/black ink for positive/negative. No user programming—the microprocessor executed fixed routines efficiently.
The 141-PF proved microprocessors viable for consumer products, sparking Intel's CPU dominance. It revolutionized electronics by showing single-chip integration could replace complex boards. Though not a "computer," its 4004 CPU paved the way for personal computing. Busicom's bankruptcy allowed Intel to market the 4004 widely. Today, surviving 141-PF units are rare collectibles (~$1,000+), symbolizing the microprocessor dawn. Titus and others cite it as inspiration for early micros.