The Distribution System

At the start of this process, we will restore the following 2311 disk volumes:

RES11A: DOS/360 system residence volume with System Core Image and relocatable module libraries, a label cylinder, IPL bootstrap records, and the distribution system supervisor. This volume does not contain any source books, so it cannot be used to assemble a supervisor.

RES11B: DOS/360 system residence volume with System Core Image and source book libraries, a label cylinder, IPL bootstrap records, and the distribution system supervisor. This volume includes source books, so it can be used to assemble a supervisor. But it cannot be used to link anything because there is no relocatable library on this volume.

RES11C: DOS/360 system residence volume with a System Core Image library, a label cylinder, IPL bootstrap records, and the distribution system supervisor. The Core Image Library on this sysres includes emulators for 1401/1410/1460 on IBM 360/30 and 360/40. The volume also has private relocatable module and source statement libraries containing the emulators, the ANSI COBOL compiler (COBOL F), and the Disk Sort/Merge program.

The DOS/360 distribution system, unlike its OS/360 counterparts did not require disks or tapes to be at any particular address. Control cards could be provided at IPL time to delete and add devices--a capability that persisted at least through DOS/VS.

Distribution System Limitations

The Distribution System supports a maximum of ten devices, including the system console, card reader, card punch, and line printer. This doesn't leave much for disk and tape drives.

I do not believe IBM ever intended the distribution system to be workable out of the box. My guess is the expectation was you would delete the stuff you did not need and reorganize things into a workable system residence volume. The documentation includes lots of information to help you delete stuff.

Distribution System Startup

While the system supports no more than ten devices, there are no devices pre-generated in the Distribution System. Control cards are used at IPL time to tell the system what kinds of devices exist at which device addresses.

This site's procedure uses a single IPL of the distribution system to collect everything required onto a single tape and create a small workable system residence volume on a (much larger) 2314 disk volume.

DOS Processing Partition

The Distribution System supported a single processing partition, and it did not have a name--it wasn't really necessary to name it because there was not a second processing partition, so no need to make a distinction.

The partition uses all available memory after the 6KB distribution system supervisor. On a real mainframe, the leftover could be as little as 10KB. On Hercules, you'll have nearly 2MB left over because the minimum Hercules emulated machine size is 2MB.

Next: Why Move to 2314 Disks?