96 Line F# Emulator + 960 bytes of HP-35 Microcode

  [Part 3 of the HP Calc series] In this post, we’ll create a 96-line F# emulator for the HP-35 calculator with which we’ll run the 960 byte (!) ROM image. As you may well know, I am a calculator freak. The 40-year-old HP-35 is an especially wonderful device; being the world’s first scientific pocket calculator….


Fixing Decades-old Bugs in the HP-35

[Part 2 of the HP Calc series] Making the JavaScript-based HP-35 microcode emulator has been a fun little project. Last time we disassembled the original bits from the ROM. I say “disassemble” but really our microcode instructions were an array of JavaScript functions. This time, I’m continuing the fun with what I’ll call an “assembler”;…


Microcode-level HP-35 Emulator (in JavaScript!)

[Part 1 of the HP Calc series] I recently started a super-geeky side hobby of collecting vintage calculators and got my hands on a pair of HP calcs. The more I learned about the internals of the devices, the more intrigued I was. Jacques Laporte has an absolutely wonderful site going into crazy detail. In…