Computer Simulation and History

This site documents SimH, a simulator for historic computer systems, as well as papers and reflections on the history of computing.

SimH (History Simulator) is a collection of simulators for historically significant or just plain interesting computer hardware and software from the past. The goal of the project is to create highly portable system simulators and to publish them as freeware on the Internet, with freely available copies of significant or representative software.

This site contains the "classic" version of SimH, the 3.X stream. This version is simpler than the 4.X stream, which can be found in a GitHub source repository. It includes all of the simulators I wrote or maintain, as well as the current releases of J. David Bryan's HP simulators. It also has a collection of papers and software kits that are applicable to all versions of SimH.


SIMH is a highly portable, multi-system simulator.

SIMH implements simulators for:

Also available is a collection of tools for manipulating simulator file formats and for cross-assembling code for the PDP-1, PDP-7, PDP-8, and PDP-11.

Software Kits to run on SIMH

Help with SIMH

System Photographs

Papers on Simulation and Historic Hardware

DEC's Microprocessors (through 1992)

Updated 08-Aug-2020 by Bob Supnik (simh AT groups DOT io - anti-spam encoded)