How Many Decimals of Pi Do We Really Need? (2016)

Re:How Many Decimals of Pi Do We Really Need? (2016) by kens on Monday September 28, 2020 @12:33PM (#24618438)

The cheap Sinclair Scientific calculator (1974) was rather primitive, so instead of storing constants internally, it printed constants such as e and pi on the case. The calculator was rather inaccurate, so you were much better off using 3.14159 from the case than computing 4×atan(1), which gave 3.1440.

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Re:How Many Decimals of Pi Do We Really Need? (2016) by taylodl on Monday September 28, 2020 @12:50PM (#24618642)

It'd be interesting to see their implementation and the trade-offs its designers made.

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Re:How Many Decimals of Pi Do We Really Need? (2016) by kens on Monday September 28, 2020 @01:24PM (#24619051)

I'm glad you asked :-) I reverse-engineered the Sinclair Scientific calculator, documented its code, and built a simulator: http://files.righto.com/calculator/sinclair_scientific_simul...

The short answer is that they used a 4-function calculator chip with just 320 words of ROM and managed to reprogram it into a cheap scientific calculator, a remarkable feat. The tradeoff was that the calculator was very slow and inaccurate.

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Re:How Many Decimals of Pi Do We Really Need? (2016) by taylodl on Monday September 28, 2020 @01:47PM (#24619325)

That's amazing! Thank you for sharing!

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