Control Program Facility (CPF) is the

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

of the IBM System/38. CPF represented an independendent line of development at IBM Rochester, and was unrelated to the earlier and more widely used System Support Program operating system. CPF evolved into the

OS/400 IBM i (the ''i'' standing for ''integrated'') is an operating system developed by IBM for IBM Power Systems. It was originally released in 1988 as OS/400, as the sole operating system of the IBM AS/400 line of systems. It was renamed to i5/OS in 2 ...

operating system, which was originally known as XPF (Extended CPF). While CPF is considered to be the operating system of the System/38, much of the hardware and resource management of the platform is implemented in the System/38's Horizontal and Vertical Microcode.

Description of the libraries

* QGPL – general purpose library * QSYS – system library * QSPL – spooling library * QTEMP – temporary library * QSRV – system service library * QRECOVERY – system recovery library

Data storage

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 (FS). 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

CPF was an example of a commercially-available Capability-based operating system. System/38 was one of the few commercial computers with capability-based addressing. Capability-based addressing was removed in the follow-on

operating system..

Distributed data management

In 1986, System/38 announced support for

Distributed Data Management Architecture Distributed Data Management Architecture (DDM) is IBM's open, published software architecture for creating, managing and accessing data on a remote computer. DDM was initially designed to support record-oriented files; it was extended to support ...

(DDM). Such a

middleware Middleware is a type of computer software program that provides services to software applications beyond those available from the operating system. It can be described as "software glue". Middleware makes it easier for software developers to imple ...

in the context of a distributed system is the software layer that lies between the operating system and applications. Distributed Data Management Architecture defines an environment for sharing data. This enables System/38 programs to create, manage, and access record-oriented files on remote System/36, System/38, and IBM mainframe systems running CICS. It also allows programs on remote System/36 and System/38 computers to create, manage, and access files of a System/38.

Programming languages

Languages supported on the System/38 included RPG III,

COBOL COBOL (; an acronym for "common business-oriented language") is a compiled English-like computer programming language designed for business use. It is an imperative, procedural, and, since 2002, object-oriented language. COBOL is primarily ...

BASIC Basic or BASIC may refer to: Science and technology * BASIC, a computer programming language * Basic (chemistry), having the properties of a base * Basic access authentication, in HTTP Entertainment * Basic (film), ''Basic'' (film), a 2003 film ...

, and

PL/I PL/I (Programming Language One, pronounced and sometimes written PL/1) is a procedural, imperative computer programming language initially developed by IBM. It is designed for scientific, engineering, business and system programming. It has b ...

. CPF also implements the

Control Language The Control Language (CL) is a scripting language originally created by IBM for the System/38 Control Program Facility and later used in OS/400 (now known as IBM i). It bears a resemblance to the IBM Job Control Language and consists of a set ...

for System/38.

References

External links

Control Program Facility Concepts Manual
(PDF file)
Control Program Facility Programmer's Guide
(PDF file) {{IBM operating systems IBM operating systems Computer-related introductions in 1978