 | This article needs more citations. (May 2019) |
| Open SIMH | |
|---|---|
| Developer | Robert M. Supnik |
| Release | 1994 |
| Written in | C |
| Operating system | Windows, Linux, macOS, FreeBSD, OpenBSD, NetBSD, OpenVMS |
| Platform | x86, IA-64, PowerPC, SPARC, ARM |
| Type | Hardware virtualization |
| License | BSD-style licenses |
| Website | opensimh |
| Repository | |
SIMH is a free and open source, multi-platform multi-system emulator. It is maintained by Bob Supnik, a former DEC engineer and DEC vice president.
SIMH was based on a much older systems emulator called MIMIC, which was written in the late 1960s at Applied Data Research.
The first version of the SIMH (History Simulator) was released by Supnik in 1994.
In May 2022, the MIT License of SIMH version 4 on GitHub was unilaterally modified by a contributor to make it no longer free software, by adding a clause that revokes the right to use any subsequent revisions of the software containing their contributions if modifications that "influence the behaviour of the disk access activities" are made. As of 27 May 2022, Supnik no longer endorses this version 4 on his official website for SIMH due to these changes, only recognizing the "classic" version 3.x releases.
On 3 June 2022, the last revision of SIMH not subject to this clause (licensed under BSD licenses and the MIT License) was forked by the group Open SIMH, with a new governance model and steering group that includes Supnik and others. The Open SIMH group cited that a "situation" had arisen in the project that compromised its principles. Open SIMH is governed by a Steering Group that includes Supnik, Clem Cole, Richard Cornwell, Paul Koning, Timothe Litt, and Seth Morabito.
The "classic" version continues to be maintained, with version 3.12-5 released on 16 July 2024. The V4 stream is available at the same Open SIMH GitHub.
SIMH emulates hardware from the following companies.
 | This emulation-related article is a stub. You can help Wikipedia by adding missing information. |