Listing of FOCAL-GT

The document provides a detailed assembly language source code listing for FOCAL-GT, developed by Robert Friedenthal and maintained by Small Systems Software Engineering at Digital Equipment Corporation in March 1973. The content includes:

• Identification and Copyright: Product details and copyright information for DEC.
• Documentation Notes: Guidelines for reading the code, including symbols for trap-instruction modules, command modules, and subroutines.
• System Definitions: Register assignments, main vectors, and public information tables (functions, interpretative tables).
• Logic and Handlers: Implementation details for command decoding, floating-point math routines, input/output control, and the GT40-specific functions (DNEW).
• Cross-Reference Table: A comprehensive index for labels and variables used within the code.