SIMH
SIMH consists of simulators for about 20 different machines, and as such, is a very important emulator for anyone interested in computer history; in particular, that of DEC systems, as the PDPs and even the VAX are well emulated by it.
It can even emulate network interfaces for the PDP-10, PDP-11 and VAX, so the emulated systems can network directly onto the Internet, if the emulated operating system supports it, like BSD or VMS.
SIMH was primarily written by Bob Supnik of Zork porting fame, and is now widely contributed to by others as well.
The current version is 3.9-0, released on May 3rd, 2012. More up to date developments may be found on their GitHub source code repository.
Contents
Emulated Systems
Altair 8800
This is the Altair 8800 emulator which can run both AltairDOS and CP/M 2.2
Altair Z80
SIMH emulates the Altair architecture with your choice of either a Z80 or Intel 8080 processor. It can run CP/M.
Honeywell H316/H516
Emulates the work horse behind the ARPANET IMPs. In 2013 the emulator was modified to bring up the original IMP code and connect them together (tunnelled over IP). Demo instructions are available in the latest source. The IMP side of the 1822 is there, but there is not much of a host side yet. I don't see anything in simh that would be able to plug in anyway. An Associated Computer Consultants (ACC) 1822 card for the pdp-11 would be a start.
HP2100
I really don't know much about this machine, but I included a way to run the basic1 program I found online. It kind of reminds me of the ROMBASIC back 'in the day'... It's basic with line numbers so I know it's kind of old.. I really don't know much otherwise about this machine.
Interdata 8/32
The Interdata 8/32 micro was the first non PDP-11 to run UNIX. SIMH can run both v6 & v7 research editions for the Interdata.
Nova
SIMH can run RDOS 7.5 for the Nova.
SIMH also includes Data General Eclipse support, but there is no available OS.
DEC PDP-1
The original PDP-1 is emulated although most of the software is expected to be toggled from the console, or loaded from paper tape. SIMH does not emulate the display needed for spacewar.
DEC PDP-6
There is a new PDP-6 emulator by Richard Cornwell.
DEC PDP-8
The PDP-8 was the first minicomputer... OS/8 runs under SIMH.
DEC PDP-10
The PDP-10 model KS10 processor is emulated and will run all but the latest versions of the TOPS-10 and TOPS-20 operating systems.
Richard Cornwell contributed a new emulator that supports KA10, KI10, KL10 model A and B, and KS10. It can run most versions of TOPS-10 and TOPS-20, as well as ITS, WAITS, and (soon) TENEX.
DEC PDP-11
The PDP-11 is emulated enough to run almost all PDP-11 operating systems including the early Unixes (v1, v4, v5, v6, v7 are known to run).
SIMH can be configured to provide simulations for the following PDP-11 models:
- PDP-11/03
- PDP-11/04
- PDP-11/05
- PDP-11/20
- PDP-11/23
- PDP-11/23+
- PDP-11/24
- PDP-11/34
- PDP-11/40
- PDP-11/44
- PDP-11/45
- PDP-11/53
- PDP-11/60
- PDP-11/70
- PDP-11/73
- PDP-11/73B
- PDP-11/83
- PDP-11/84
- PDP-11/93
- PDP-11/94
MicroVAX II
The SIMH microvax2 simulator can run the MicroVAX II with as much as 16 MB of emulated RAM.
Both VMS, ULTRIX, NetBSD, OpenBSD and original BSD can run on this emulator.
With the following SIMH commands you can choose between three MicroVAX II models:
- Standard MicroVAX II: SET CPU MODEL=MicroVAX
- MicroVAX II with four Plane Graphics (Mono or Color): SET CPU MODEL=VAXstation
- MicroVAX II with eight Plane Graphics (Color): SET CPU MODEL=VAXstationGPX
VAX 11/780
SIMH can also simulate the first model of the VAX, the VAX-11/780, the name of the simulator is vax780.
This is appropriate for older operating systems like VMS release 1.x (see: Installing VMS V1.0 on SIMH) and the original 32v, 3.0 BSD and all 4BSD releases, e.g. 4.0 BSD.
Usage
SIMH can either take in configuration parameters interactively, or you can store them in a file. If the file is the name of the emulator+.ini it will load them automatically (eg vax.exe loads vax.ini automatically). The CONTROL+E key will break the emulation and bring you back to the SIMH console where you can alter the running state.
Networking is covered in the Networking with SIMH guide.
Support
While not immediately obvious, there is a mailing list here http://mailman.trailing-edge.com/pipermail/simh/. I would recommend searching the thing, and you'll be amazed how much good information there is in there. Likewise, I'd recommend joining the list if you are interested in running SIMH. You can join here. As 4.0 is still in beta, the public source repository is also a great source of information.
