Control Program Facility


Control Program Facility was the operating system for the IBM System/38. CPF is not related to SSP.

Overview

A database management system was integrated with the operating system.
The System/38's advanced operating system lives on with IBM's AS/400. Great efforts were made by IBM to enable programs originally written for the System/34 and /36 to be moved to the AS/400.

Description of the libraries

In most computers prior to the System/38, and most modern ones, data stored on disk was stored in separate logical files. When data was added to a file it was written in the sector dedicated to this, or if the sector was full, on a new sector somewhere else.
The System/38 adopted the single-level store architecture, where main storage and disk storage are organized as one, from the abandoned IBM Future Systems project. Every piece of data was stored separately and could be put anywhere on the system. There was no such thing as a physically contiguous file on disk, and the operating system managed the storage and recall of all data elements.

Capability-based addressing

System/38 was one of the few commercial computers with capability-based addressing. Capability-based addressing was removed in the follow-on AS/400 and iSeries models. Capability-based operating system refers to an operating system that uses capability-based security.