FRAP - An Assembly for PDP-1

This document provides an in-depth guide to FRAP, an assembly program designed for the PDP-1 computer with a minimum of 1024 words of memory. It covers the symbolic program structure, including statements, words, and delimiters, and details how FRAP uses symbols and numerical values. Key sections include:

• Program Structure: Explains how to write a program using symbolic operation codes, origin statements (org), and how the compiler processes input to produce an output tape.
• Control Words: Provides a comprehensive list of operators available in FRAP, such as opd (operation definition), loc (location), end, and mathematical operators like + and -.
• Operational Procedures: Details the process for assembling a program, including the use of sense switches for controlling compiler behavior and performing zero passes for multi-program systems.
• Error Indications: A reference table explaining computer halts to help troubleshoot during assembly.
• Addendum: Includes updates from 22 January 1961 regarding new symbols and operational changes.

The document concludes with a full symbol definition list including operation groups, in-out transfer groups, and shift-rotate instructions.