: New drivers for MPCPTP/MPCPTP6 devices, IBM 3791 support, and QDIO/OSA support. Architecture Compliance
Previous versions required restarting Hercules to add or remove virtual devices. Version 4 introduced of CTCI (channel-to-channel) adapters, network devices, and tape drives—critical for testing mainframe production scenarios. hercules-390 version 4
ARCHMODE ESA/390 # or Z/ARCH for 64-bit CPUSERIAL 000123 CPUMODEL 3090 MAINSIZE 512 # memory in MB LOADPARM 0120 OSTAILOR MVS : New drivers for MPCPTP/MPCPTP6 devices, IBM 3791
Moreover, Version 4 introduced enhanced console support via the hercules HTTP server and integrated telnet line-mode terminals. This allowed a modern network of users to connect to a single emulated mainframe, each accessing a 3270 terminal session through a web browser or open-source tn3270 client. The democratization was staggering: a university computer science department could now teach JCL, COBOL, and CICS without a million-dollar IBM contract. ARCHMODE ESA/390 # or Z/ARCH for 64-bit CPUSERIAL
The “Hyperion” moniker (used in source code) reflects that Version 4 is a “hard fork” of the classic Hercules 3.x line, designed to address technical debt, improve cross-platform consistency, and embrace modern development practices.
One of the most profound impacts of Hercules-390 Version 4 was its role as a . Countless organizations had legacy data and applications trapped on aging System/390 hardware—machines with failing power supplies, magnetic tape drives, and proprietary disk packs. Version 4 provided a migration path: using tools like dasdload and tape2file , administrators could create exact disk and tape images from physical media and run them unaltered on the emulator.
Performance saw a quantum leap through threaded interpretation and dynamic basic block chaining. While earlier versions relied on a simple instruction fetch-decode-execute loop, Version 4 implemented a just-in-time (JIT)-like translation mechanism for frequently executed code sequences. On a modern multi-core Intel or AMD processor, a Hercules-390 Version 4 instance could outperform a physical 1990s CMOS mainframe by a factor of ten to twenty, turning a $500 desktop into a virtual data center powerhouse.