Screen shot of SimHYMN v1.0d, released February 2004
SimHYMN simulates a simple 8-instruction CPU and 32-byte memory designed for learning about how a CPU executes a program. The CPU contains three registers: IR (instruction register), PC (program counter), and AC (accumulator). The eight instructions are as follows.
SimHYMN should run on any platform having Java 1.4. The program is free for your personal use, though you cannot distribute it to others.
If you enjoy SimHYMN, you might also enjoy Logisim.