Prime and Saturn calculators

[Steve Simpkin]

(07-05-2024 07:57 PM)dm319 Wrote:  That's very interesting! I wonder how deep the emulation goes - I would have thought it would need to emulate the 15 digit BCD to give the pretty much identical results, but I could be wrong about that.

So when the most recent Prime was introduced in 2018, it was using 31 year old code, now 37 years.

I see further down that second thread that someone mentions the HP-12c source code went missing. I wonder if that was before or after the HP-12c platinum, which shares some similarities to the original HP-12c, but seems to work on a 12 digit platform.

I don't believe any of the math code used in the HP Prime is that old. My understanding it that it was entirely new code written to mimic the behavior of the original Saturn math libraries.

"In 2004 or so, when it became clear that we would be working more and more with ARM chips for low end calcs, I recreated the whole math library in C, but as a recreation based on the code rather than a copy. This library is what is used in Prime and a couple of other calcs..."

The math library and algorithms used in the HP-12C Platinum was not written by HP at all. HP provided a detailed set of specifications for the functionality of the HP-12C Platinum and its form factor to an outside contractor (perhaps Kinpo Electronics). That company then designed the calculator circuitry, hardware, wrote the software and manufactured the calculator for HP. The HP 33s and HP 35s went through a similar process. They are all using a variations of a Sunplus CPU which has a core based on the 6502 microprocessor.
https://en.wikipedia.org/wiki/HP-12C#HP_.../_Prestige
https://en.wikipedia.org/wiki/HP_33s
https://en.wikipedia.org/wiki/HP_35s