Fairchild PPS-25: The 1971 4-bit CPU Designed for 25-Digit Precision Calculations
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Summary
The article discusses the Fairchild PPS-25, a 4-bit CPU from 1971 designed for 25-digit precision calculations. It was developed by Fairchild Semiconductor after losing key employees to Intel and AMD, operating at 400KHz with a 62.5μs word cycle. The piece covers the historical context of early microprocessor development, positioning the PPS-25 alongside contemporaries like the Intel 4004 and TI TMS1000 as part of the forgotten early computing pioneers.
Key quotes
· 3 pulledThis brings us to 1971, Fairchild, after losing many employees in 1968-69 who went on to start world famous semiconductor companies (Intel and AMD amongst others) has decided to make their own processor system.
The PPS-25 is a 400KHz (62.5uS Word cycle
This was very early in the era of CPUs, you had the Intel 4004, the TI TMS1000, and various calculator type circuits.
Article URL: https://www.cpushack.com/2025/02/01/fairchild-pps-25-4-bit-cpu-for-25-digit-precision/
Comments URL: https://news.ycombinator.com/item?id=45269673
Points: 3
# Comments: 0
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