Not my interest, but thought others on the list would like it: PDP-8/E Simulator, from Bernhard Baehr, emulates the classic Digital Equipment PDP-8/E minicomputer with software that runs on a Mac. Features include a "comfortable user interface" for running, writing and debugging PDP-8 software; viewing and editing memory; breakpoints, single step execution, and a trace mode; a plug-in API; a programmer's console; a virtual TSC8-75 board to run the ETOS time sharing OS; an ASR 33 Console Teletype, ASR 33 Auxiliary Teletype, PC8-E High Speed Paper Tape Reader and Punch, a RK8-E Disk Cartridge System and more. PDP-8/E Simulator is free, open-source software for PowerPC and Intel Macs running Mac OS X 10.4 and up. Benchmarks show that the PDP-8/E Simulator outperforms a hardware PDP-8/E in orders of magnitude when running on reasonable current Macs. There are options to slow down the CPU and the I/O devices to the speed of the real hardware. http://www.bernhard-baehr.de/pdp8e/pdp8e.html