TOPS-10/TOPS-20 DDT11 Manual

This manual describes DDT11, a symbolic debugging program designed for use by system support specialists on TOPS-10 and TOPS-20 host systems. Its primary purpose is to diagnose and correct errors in PDP-11 based front ends and remote nodes, modify running software, and examine system states.

Key functionalities of DDT11 include:

• Memory Examination and Modification: Users can examine and deposit data into memory on running nodes, dump files, and unrun system images. This involves moving a location pointer, displaying contents in various formats (numeric, symbolic, byte, ASCII, IBM), and searching for specific words using masks.
• Execution Control: The program allows for starting execution, simulating single instructions, and executing subroutine calls.
• System and Node Support: DDT11 provides specific procedures for interacting with different communication products and front ends, including ANF-10 nodes, IBMCOM front ends, DECnet-10/DECnet-20 front ends (MCB nodes), and RSX-20F front ends. This often involves loading product-specific symbol files (.CRF, .MAP, .STB) to enable symbolic debugging.
• Symbolic Debugging: It offers features for defining symbols, controlling their typeout, and matching or completing partial symbols.
• Monitoring and Dumping: Users can monitor specific memory locations for changes and dump portions of memory to disk files.
• Command Files: Support for command files with macro-style arguments and tags enables automated debugging tasks and conditional branching.
• Binary File Output: Modified memory contents can be written to new binary files using various switches for specific formats (e.g., for ROMs, task images, or packed binary files).

The document is intended for moderately to very experienced users familiar with TOPS-10/TOPS-20 systems, network configurations, and standard DDT.