PDP-9/339 Graphics Subprogram Package

This document provides a comprehensive guide to the PDP-9/339 Graphics Subprogram Package. It covers the necessary subroutines and functions that allow user programs, written in FORTRAN IV or Macro-9, to interact with the 339 graphic display device without needing deep hardware knowledge. Key sections include:

• Introduction: Overview of the system and required software.
• Graphic Subprogram Routines: Detailed documentation for calling statements to generate and manipulate subpictures, display files, and handle input.
• System I/O Device Handler: Explanations of macros used to manage communication between the PDP-9 and the display controller, including initialization and interrupt management.
• Appendix A: Sample FORTRAN programs demonstrating practical use of the library.