Modifications to TSS/8 FOCAL

This document outlines two functional modifications made to the TSS/8 FOCAL system as of early 1970. First, it introduces the ability to use arithmetic expressions as targets in branching statements. Second, it adds functionality for storing and retrieving FOCAL programs directly to and from disk storage using the LIBRARY SAVE and LIBRARY RETRIEVE commands (or the abbreviated L S and L R commands).

These patches were designed to occupy existing memory areas previously assigned to high-speed paper tape reader routines, the library command, and the binary loader, ensuring that no active text or pushdown space is consumed. The document includes technical details, source code patch listings, and example usage scenarios.