DEC Debugging Tape

This document describes the DEC Debugging Tape (DDT) program for the PDP-1, designed to streamline the debugging process by enabling users to control, examine, and modify their programs directly at the computer. Key features include:

• Real-time Debugging: Allows users to insert patches, set breakpoints, and modify data or instructions without needing to reassemble the entire program.
• Breakpoint Facility: Provides tools to interrupt program execution at specific points to inspect the machine state.
• Symbolic Interaction: Maintains a symbol table, enabling programmers to communicate with the computer using the symbolic names from their own programs.
• Command Set: Detailed documentation is provided for commands covering program loading, tape punching, register examination/modification, mode control, searching, and program execution control.

An appendix specifically covers "Extend DDT-1," describing features for PDP-1 configurations with Memory Extension Control and additional hardware modules.