Debug80 Docs

Debug80 Book 1 — Getting started105

Appendix E — Local monitor ROM source ​

Debug80 supplies the platform monitor ROM for ordinary TEC-1 and TEC-1G projects, so a project-local copy is needed only to study, edit or debug the monitor itself. Debug80 then assembles the copied files with AZM and uses their source map when execution enters monitor code.

The copy command ​

The VS Code Command Palette opens with:

  • macOS: Shift-Command-P
  • Windows and Linux: Shift-Control-P

Debug80: Copy Monitor ROM into Project starts the copy.

Debug80 asks which workspace folder should receive the monitor source.

When files already exist, Skip existing files preserves local edits. Overwrite existing files replaces them with a fresh copy of the shipped monitor source.

Files created ​

For a TEC-1G / MON-3 project, Debug80 creates a local ROM entry file:

text
roms/tec1g/mon3/mon3.rom.asm

For a TEC-1 project, the local entry file is:

text
roms/tec1/mon1b/mon1b.rom.asm

The TEC-1G entry file includes the copied MON-3 source:

asm
.include "mon3.z80"

The copied source files live under the same roms/tec1g/mon3/ folder.

Building the local ROM ​

After the copied ROM source is edited, Run assembles it with AZM, writes the generated artifacts under build/roms/, and starts the machine on that ROM instead of the bundled one. Build alone assembles it without launching.

Once a *.rom.asm file exists, every launch builds it and points the platform at the result, whatever ROM debug80.json names. A forgotten monitor source in roms/ can therefore explain unexpected project behaviour because it replaces the configured monitor.

For TEC-1G / MON-3, the generated files include:

text
build/roms/tec1g/mon3/mon3.hex
build/roms/tec1g/mon3/mon3.d8.json

The .d8.json file is the source map for the local monitor build. Debug80 uses it for source breakpoints, stepping and source navigation inside the copied monitor files.

Debugging monitor code ​

Breakpoints in copied ROM source files behave like breakpoints in the program source.

Stepping into monitor services now opens project-local files under roms/tec1g/mon3/ instead of the bundled source files from the extension.

Returning to the bundled ROM ​

Removing the platform's local *.rom.asm entry file returns the project to the bundled monitor ROM. For TEC-1G / MON-3 that file is:

text
roms/tec1g/mon3/mon3.rom.asm