OS/360 on Hercules: Getting started

2. Getting started

2.1 The host system

Hercules runs on most current Linux distributions, Mac OS X, other Unix-style systems, and Windows 98 and above. It will make use of multiple host CPUs if present, and benefits greatly from having enough main memory to allocate all of the emulated system's cenral storage plus approximately 128 MB for the host OS to use. Hercules can emulate multiple CPUs, but that function will not be used in the generated MVT system, mainly because nobody has tested it to see if it works.

2.2 Hercules

You'll need the current revision of Hercules. Download it from the Hercules home page. You can install the prebuilt binaries, if they're available for your host system; if not, you'll get to build it yourself.

The current version as I write this is 3.02. Earlier 3.x and 2.x versions will probably work, although 2.16.x is known to have problems with MVT. 1.x versions will not work with the configuration files shipped as part of this package.

2.3 The OS/360 distribution

The best source is the CBT CD-ROM, which contains Rick Fochtman's OS/360 distribution. This has not only the OS/360 distribution files, but also the source to the operating system and utilities, as well as some useful documentation. There are many, many other useful files and utilities on the disk, and it's a must for anyone wanting to experiment with OS/360, as well as any systems programmer on a modern OS/390 or z/OS system. Ordering information is at the CBT Tape site.

2.4 JCL and control files

I've packed up the JCL, control files, replacements for files missing from Rick's distroibution, and HASP installation tapes in one handy place for downloading. Save this file as os360ctl.tar.gz in your Hercules directory, then unpack it:
tar xzvf os360ctl.tar.gz
It'll create a subdirectory named os360mvt, where all your work will be done. I'll reference the files by name throughout the rest of this document.

2.5 Patience!

This whole process will take an hour or so. On a 500 MHz Pentium III laptop with 384 MB of RAM, stage 1 ran for me in about 1 minute, and stage 2 about 5. If you go messing around with the JCL, especially with the dataset allocations for the target system, you won't know if there's a problem until about halfway through stage 2, and the easiest way to recover is to start over from scratch. The JCL and control files in the os360ctl.tar.gz file produced a clean system for me; I don't recommend messing with them until you've had a successful build, and then only if you really know what you're doing. This was a bigger problem when stage 2 took two hours to run, but it's still sound advice.

Up to table of contents Previous: Overview Next: Building the driving system

Jay Maynard, jmaynard@conmicro.cx

Last updated 29 April 2005