FOCL/F - An Extended Version of 8K FOCAL/69

FOCL/F is a powerful, extended version of the 8K FOCAL/69 programming language, designed to increase versatility in scientific, engineering, and educational environments. It introduces significant enhancements, including user-defined functions with recursion, user-defined interrupt service, machine language instruction execution, arrayed variables, and expanded input/output controls. The document details the language's command set, architectural improvements such as efficient core storage and direct address computation, and provides extensive technical documentation for error messages and compatibility, specifically addressing its usage in PDP-8/E environments and with PS/8 overlays.