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SDL Hyperion
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The SoftDevLabs version of Hercules 4.x (Hyperion)


  1. About
  2. Find out more
  3. Additional README files


Hercules is an open source software implementation of the mainframe System/370 and ESA/390 architectures, in addition to the latest 64-bit z/Architecture. Hercules runs under Linux, Windows, Solaris, FreeBSD, and Mac OS X.

Hercules is OSI Certified Open Source Software licensed under the terms of the Q Public Licence.

This version of Hercules 4.x Hyperion is a SoftDevLabs maintained version of the Hercules emulator containing fixes made by myself and others for bugs that may still exist in the original hercules-390 version of Hercules 4.0 Hyperion, as well as enhancements and improvements to the overall functionality above and beyond what is provided by the hercules-390 version of Hercules.

Hercules was created by Roger Bowler.

Jay Maynard "the Tron Guy" was the maintainer from 2000 to 2012.

Jan Jaeger designed and implemented many of the advanced features of Hercules, including dynamic reconfiguration, integrated console, interpretive execution and z/Architecture support.

The SoftDevLabs version of Hercules 4.x Hyperion is currently the only 'active' version of the Hercules emulator in existence (so it seems).

Find out more

To find out more about this particular version of Hercules 4.x Hyperion, follow this link: Hercules 4.x (Hyperion)

Additional README files


Unresolved Issues

Bug reports (together with your diagnosis of the fault please!) should be reported to our bug report tracking system by adding/creating a new "GitHub Issue" on GitHub.

Building Hercules

Building Hercules (Overview)   (Important!)
Building "External Packages"   (Important!)
Building Hercules under AIX
Building Hercules under BSD/OSX
Budiling Hercules for OSX
Building Hercules under 64-bit Windows
Building Hercules with MinGW   (obsolete)
Building Hercules for Windows with Visual C   (obsolete)
HercIFC and Hercules as setuid root programs
How to build Hercules from SVN under Solaris


APL/360 mods
ECPS:VM & Extended VM Assists
Preliminary 2703 BSC Support

Features and Operation

Customizable Hercules 3270 Logo
Guest Access To Host IP Stack - The TCPIP (X'75') Instruction
HAO (Hercules Automatic Operator)
Hercules CCKD64 Support
Hercules Networking
Hercules REXX Support
Hercules Tape Support Enhancements SPE/Fixes
Host Resource Access Facility
Runtest Low-level Test Cases
S/370 Backport of select ESA/390 and z/Architecture instructions
TCPNJE Support
VMFPLC2 (VM) Formatted Tape Utility


Adding New Files to Hercules
Adding New z/Architecture Facilities to Hercules
CMPSC "Compression Call" instruction support
Hercules Dynamic Loader
Hercules Dynamic Modules (on Windows)
HQA Build Scenarios
Input/Output Architecture
Low-level Test Cases
PTT Tracing