Postmarks

"PlasMa simulates a complete mini/mainframe system in a self-contained desktop-sized box containing real lights and switches. The system comprises a simulated 'mini-like' processor with a small amount of main memory, and simulated 'mainframe-like' peripherals such as a paper tape reader and punch, mag tapes, exchangeable disks and an operators console. The processor is 'micro-coded' and can run (currently) 3 different instruction sets; two based on the Princeton TOY architecture with 2K words memory for educational use, and a more advanced home-grown ISA based on NICE, with 64K words memory and floating point. The simulation runs on an ATmega2560 MCU which also controls the user-interface comprising approx 540 LEDs, 100 switches, 6 SD-cards, LCD screen, keypad, speaker, and interfaces for a PS/2 qwerty keyboard and MIDI."