Micro-PL/CS is a version of PL/CS developed for interactive use with a dedicated microprocessor. A file system extension is proposed to give PL/CS a simple, but extremely powerful file system capability. The system allows for the creation and manipulation of files for sequential, random, or keyed access (or any combination) in an unrestricted manner. Essential to the capability is a set of built-in functions and pseudo-variables which allow file manipulation without syntactic complication.