Online HP-35 Emulator - First scientific pocket calculator from 1972

[van2z]

I love building emulators. The HP-35 was quite fun because it actually has two separate CPUs - The HP Control & Timing chip and the HP Arithmetic & Register chip. 3 ROM chips, and no RAM chips. Here it is:

https://veniamin-ilmer.github.io/hp35/

I like to emulate each chip as accurately as possible, with all clock timings the same as the original.

It works in mobile and desktop. Desktop view shows register data.

As an imprecise but fun measure, I checked the compiled code's size of this HP-35 emulation vs my Busicom 141-PF emulation, which used the Intel 4004.

HP-35 was 39 KB. Busicom was 43 KB. Yet the most advanced math function in the Busicom 141-PF, was doing a square root.