HP-45 emulator

Simulates the CPU of an HP-45 calculator. Can be ported to embedded project like 8051, AVR, ARM CM3, etc.

Features

• Written in plain C: platform independent.
• All memory and CPU states are wrapped in struct: supports multi-instance.
• Easy to use: only 5 functions in user interface.
  • hp45_key_down and hp45_key_up: notify CPU that a key is pressed/released.
  • hp45_init: initializes instance struct.
  • hp45_run: performs a single step.

Usage

To simulate the HP-45 at actual speed:

1. call hp45_init once
2. call hp45_run once per 286us (precisely speaking, 35 times per 10ms).
3. (optional) call make_display to convert CPU registers into display buffer for LED scanning.