Hercules (emulator)
Original author(s) | Roger Bowler |
---|---|
Developer(s) | Jay Maynard, Jan Jaeger, David "Fish" Trout, Greg Smith, Bernard van der Helm, Ivan Warren, and others[1] |
Initial release | 1999 |
Final release | 3.13
/ 29 September 2017 |
Preview release | 4.0.0-rc0
/ December 16, 2016 |
Cross-platform | |
Type | Emulator |
License | Q Public License |
Website | www |
Developer(s) | Jay Maynard, Jan Jaeger, David "Fish" Trout, Greg Smith, Bernard van der Helm, Ivan Warren, and others[2] |
---|---|
Stable release | 4.6.0
/ June 9, 2023 |
Repository | github |
Predecessor | Hercules 4.0.0 Release Candidate 0 |
Website | sdl-hercules-390 |
Hercules is a computer
Hercules runs under multiple parent
Design
The emulator is written almost entirely in C. Its developers ruled out using machine-specific assembly code to avoid problems with portability even though such code could significantly improve performance. There are two exceptions: Hercules uses hardware assists to provide inter-processor consistency when emulating multiple CPUs on SMP host systems, and Hercules uses assembler assists to convert between little-endian and big-endian data on platforms where the operating system provides such services and on x86/x86-64 processors.
Operating systems status
Hercules is technically compatible with all IBM mainframe operating systems, even older versions which no longer run on newer mainframes. However, many mainframe operating systems require vendor licenses to run legally. Newer licensed operating systems, such as
Operating systems which may legally be run, without license costs, on Hercules include:
- Older IBM operating systems including TSS/370 which are either public domain or "copyrighted software provided without charge."[4]
- The MUSIC/SP operating system may be available for educational and demonstration purposes upon request to its copyright holder, McGill University. Some of MUSIC/SP's features, notably networking, require z/VM (and thus an IBM license). However, a complete demonstration version of MUSIC/SP, packaged with the alternative Sim390 mainframe emulator, is available.
- The Michigan Terminal System (MTS) version 6.0A has been tailored to run under Hercules.[5]
- There is no known legal restriction to running . Sine Nomine Associates brought OpenSolaris to System z, relying on features provided by z/VM. Emulation of those specific z/VM features for OpenSolaris is included starting with Hercules Version 3.07.
- Certain unencumbered editors and utilities which can run on a mainframe without a parent operating system may be available to run on Hercules as well.
- PDOS/3X0 (Public Domain Operating System, mainframe version)
Usage
Hercules can be used as a development environment to verify that code is portable (across Linux processor architectures, for example), supports symmetric multiprocessing (SMP), and is 64-bit "clean."
There is also a large community of current and former mainframe operators and programmers, as well as those with no prior experience, who use Hercules and the public domain IBM operating systems as a hobby and for learning purposes[citation needed]. Most of the skills acquired when exploring classic IBM mainframe operating system versions are still relevant when transitioning to licensed IBM machines running the latest versions[citation needed].
The
Performance
This section needs additional citations for verification. (February 2014) |
It is difficult to determine exactly how Hercules emulation performance corresponds to real mainframe hardware, but the performance characteristics are understandably quite different. This is partially due to the difficulty of comparing real mainframe hardware to other PCs and servers as well as the lack of concrete, controlled performance comparisons. Performance comparisons are likely legally impossible for licensed IBM operating systems, and those operating systems are quite different from other operating systems, such as Linux.
Hercules expresses its processing performance in
Tom Lehmann, co-founder of TurboHercules, wrote:
...We can run a reasonably sized load (800 MIPS with our standard package). If the machine in question is larger than that, we can scale to 1600 MIPS with our quad Nehalem based package, and we have been promised an 8 way Nehalem EX based machine early next year that should take us to the 3200 MIPS mark. Anything bigger than that is replicated by a collection of systems.[7]
Hercules generally outperforms
Note that there are other non-functional system attributes[
TurboHercules
In 2009, Roger Bowler founded TurboHercules SAS, based in France, to commercialize the Hercules technology. In July 2009, TurboHercules SAS asked IBM to license z/OS to its customers for use on systems sold by TurboHercules. IBM declined the company's request.[8] In March 2010, TurboHercules SAS filed a complaint with European Commission regulators, alleging that IBM infringed EU antitrust rules through its alleged tying of mainframe hardware to its mainframe operating system, and the EC opened a preliminary investigation.[9] In November 2010, TurboHercules announced that it had received an investment from Microsoft Corporation.[10] In September 2011, EC regulators closed their investigation without action.[11]
See also
- PC-based IBM-compatible mainframes – z/Architecture and today
References
- EU: Hercules 390
- ^ "6.1", FAQ, GitHub: SDL Hercules 390
- ^ Licenses by Name (alphabetical) (list), Open Source Initiative, 16 September 2022
- ^ "2.02. What operating systems can I run legally?", Frequently-Asked Questions, EU: Hercules 390 Version 3.
- ^ "Michigan Terminal System Archive". Archived from the original on 11 January 2011. Retrieved 10 December 2022.
- ^ "S/380 Description", MVS/380 project, Sourceforge.
- ^ Hercules goes commercial! (Web log), Oracle, archived from the original on 10 October 2016
- ^ Exchange of letters between TurboHercules and IBM, Turbo Hercules, archived from the original on 12 October 2011.
- ^ Antitrust: Commission initiates formal investigations against IBM in two cases of suspected abuse of dominant market position, European Commission, 26 July 2010.
- ^ News Release (PDF), TurboHercules, 23 November 2010, archived from the original (PDF) on 10 March 2012.
- ^ Antitrust: Commission market tests IBM's commitments on mainframe maintenance and closes separate case into alleged unlawful tying, EC, 20 September 2011.
External links
- Hercules (emulator) at Curlie
- Hercules, Son of Z's (Review on Tech-news.com)
- CBT tape has a collection of IBM mainframe operating systems and of other software
- Public domain software archive (includes Turnkey MVS CD image)