Control Program Facility (CPF) is the operating system of the IBM System/38.
[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.
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.
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.
Languages supported on the System/38 included RPG III, COBOL, BASIC, and PL/I.