Note: This section is in the archived section - no longer under development and likely out of date.


This section provides information and downloads for people interested in IBM Mainframes - especially those who want to research and learn about them but who do not have access to a real mainframe!

The key tool is Hercules an open source software implementation of the mainframe System/370 and ESA/390 architectures, in addition to the new 64-bit z/Architecture. Hercules runs under Linux, Windows (98, NT, 2000, and XP), Solaris, FreeBSD, and Mac OS X (10.3 and later).

An MVS distribution exists - Turnkey.

See also Jay Moseley's page.


OS/380 are the family of freely-available 31-bit mainframe operating systems which includes MVS/380 and VM/380.


MVS/380 is not distributed as a standalone product, but instead provides a framework. It currently makes use of turnkey-mvs(a distribution of MVS 3.8j from Volker Bandke and others). It also relies on an independent party to provide the equivalent of a CBIPO (An IBM acronym for "Custom-Built Installation Process Offering"), in the form of shadow files.

We have hosted a pre-built "CBIPO" (84,552.6 kB) - below in the file downloads (you need to be logged on to access this).


VM/380 is also distributed as shadow files predicated on the current version of VM/370 (see next section).


The VM/370 "SixPack" version 1.0 rolls up all of the modifications posted on the H390-VM and Hercules-os380 Yahoo groups since the "5-pack" system was released in 2006.

The base operating system is IBM's VM/370 Release 6 operating system, the last unlicensed version of VM/370.  It is designed to run on the Hercules Emulator.

New features of the "SixPack" include:

  • An up-to-date, accurate, and fairly complete help system.
  • The Gnu C Compiler, with both a "traditional" runtime library (PDPCLIB) and a "native CMS" runtime library (GCCLIB). Type HELP GCC for information on compiling C programs.
  • Extended parameter list support, meaning it is possible to pass mixed-case parameters to EXECs and C programs.
  • Current line highlighting and multifile editing in EDIT.
  • Other programs such as DIFF, FLIST, RESLIB, SCAN, VMARC are all available on the CMS Y disk.
  • This version of VM/370 is brought to you by Robert O'Hara, Paul Edwards, and Dave Wade.  It is based on earlier versions of VM/370 for Hercules developed by Andy Norrie and Paul Gorlinsky.
  • The distribution is hosted in the downloads section (see below) -

MVS380 Single Archive Wrapper

Note - This file is now out of date (previous BETA version of MVS/380)

I have included a rather large file - - which is a zip file of the DASD and config files created created after following the MVS/380 instructions.  

This distribution is an extension of Turnkey. The original creator of the Turnkey distribution is Volker Bandke. The maintainer of the TK3SU1 BETA update to Turnkey TK3 version is Phil Roberts. The creator of MVS380 is Paul Edwards and others.

Note - I have provided this in good faith but it has only been tested by me!

File Downloads

As a simple mechanism to avoid unnecessary downloads (considering the size of some of the files) you must be logged on to access the files.

Note: Registration is free, automated and quick.

Please Login or Register with the forms on the left. After logging on you will need to re-select the Mainframe section - apologies that this process is a bit clumsy!

Important TK3SU1.ZIP Distribution and License Issues

A complaint was received about making TK3SU1.ZIP available for download. Please see this report details.

The TKSU1.ZIP file was hosted until the 15 June 2009. It was hoped that the Turnkey, MVS/380 and MVS 3.8 community would come together to produce an acceptable distribution before this date. Although MVS/380 has made progress the Turnkey community has not to date produced an update. For the avoidance of doubt TK3SU1.ZIP is no longer available.