A method, memory system, and program product is described for providing
extended functions in a digital device conforming to an intercompartment
language specification. The method involves preparing a list of unused
opcodes according to a version of the language of one compartment, and
publishing the list of unused opcodes to code of a second compartment.
Code of the second compartment then assigns opcodes to extended functions
such that the opcodes assigned are unused opcodes in the version of
language of both compartments. The assigned opcodes are used in
generating code in the intercompartmental language, and published as a
table of assigned opcodes with associated function names to the first
compartment.