Micron Document




Control Program Facility
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Control Program Facility (CPF) is the operating system of the IBM System/38.cite-ref-3[3] 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 operating system, which was originally known as XPF (Extended CPF).cite-ref-inside-as400-1-1[1]

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.cite-ref-inside-as400-1-2[1]cite-ref-4[4]

Contents


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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).cite-ref-5[5] 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.cite-ref-6[6] Capability-based addressing was removed in the follow-on OS/400 operating system.cite-ref-soltis2001-7-0[7]

Distributed data management

In 1986, System/38 announced support for Distributed Data Management Architecture (DDM). Such a middleware 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, BASIC, and PL/I. CPF also implements the Control Language for System/38.cite-ref-8[8]

References

cite-note-inside-as400-11. citereffrank-g-soltis1997Frank G. Soltis (1997). Inside the AS/400, Second Edition. Duke Press. ISBN 978-1882419661.
cite-note-21. "IBM SYSTEM/38 CONTROL PROGRAM FACILITY RELEASE 8 AVAILABLE WITH ENHANCEMENTS". IBM. 1986-10-07. Retrieved 2021-04-07.
cite-note-33. IBM System/38 Technical Developments (PDF). IBM Product Design and Development, General Systems Division. 1980 [1978]. ISBN 0-933186-03-7. G580-0237-1.
cite-note-44. citerefsoltis1981Soltis, Frank (September 1981). "Design of a Small Business Data Processing System". IEEE Computer. 14: 77–93. doi:10.1109/C-M.1981.220610. S2CID 398484.
cite-note-55. citerefmark-smothermanMark Smotherman. "IBM Future System (FS) - 1970s". Retrieved October 11, 2017.
cite-note-66. citereflevy1984Levy, Henry M. (1984). "The IBM System/38" (PDF). Capability-Based Computer Systems. Digital Press. ISBN 0-932376-22-3.
cite-note-soltis2001-77. citerefsoltis2001Soltis, Frank G. (July 2001). Fortress Rochester: The Inside Story of the IBM ISeries. 29th Street Press. p. 119. ISBN 978-1-58304-083-6..
cite-note-88. "IBM System/38 Control Language Reference Manual" (PDF). IBM. 1982-09-10. Retrieved 2021-03-24.

External links

• Control Program Facility Concepts Manual (PDF file)
• Control Program Facility Programmer's Guide (PDF file)