Introduction to U/W-FOCAL for the PDP/8

This document is a technical manual for the U/W-FOCAL language, an advanced, stack-processing, interactive programming language designed for the PDP/8. The manual covers system hardware requirements, loading procedures, language syntax, command structure, editing tools, and input/output control. It provides detailed explanations of arithmetic operators, internal functions, protected and subscripted variables, and program defined functions (PDFs). Additionally, it includes appendices regarding memory patches and error diagnostics.