Fortran for the PDP-1

This document serves as a user manual and technical guide for the FORTRAN compiler designed for the PDP-1 computer, as distributed by the Digital Equipment Computer Users Society (DECUS) in 1965.

Summary of Contents:

• System Overview: The manual explains that the compiler is intended for shorter programs and is provided in two versions: one for machines using subroutine-based arithmetic (Version 1) and one for machines with dedicated hardware for multiply/divide operations (Version 2).
• Language Specifications: The guide details the supported syntax, including constant definitions, arithmetic statements, available math functions, control flow (GO TO, IF, DO loops), and input/output procedures.
• Operation: It outlines the seven-tape process required to compile, link, and execute programs, including specific instructions for loading the compiler, the DECAL loader, and the necessary subroutine packages.
• Error Handling: The document provides a comprehensive list of error codes that the compiler may trigger, as well as common runtime errors, their meanings, and possible troubleshooting steps.
• Technical Appendices: The manual includes details on special features (such as escape characters), instructions for using DECAL inserts, and a complete annotated sample program for sorting numbers, along with its corresponding system output.