The source code for this ROM is public domain; however, the characters are not, and are copyright © 2004 by Bob Rost. You are free to use the provided source code in any way you see fit, but you may not use the accompanying artwork or characters, except for private educational use, or with prior permission from Bob Rost.
The source directory contains various nbasic files. Each one is the entire demo at a particular stage in development. The source files were saved after each major feature was implemented, so that you can compare them to see how to move from one step to the next. Consider using the program diff for comparing the versions.
The provided build script currently uses main.bas to build the rom. You may change the build script, or compile by hand, to use any of the other provided source files instead. Note that main.bas is a copy of tomley10.bas, so you should feel free to modify it without fear of losing anything.
The data directory contains the CHR and level data files used by the game, as well as various bitmap images used in generating them with some of Bob Rost's NES graphics tools.
Graphics tools you may wish to look at, for the purposes of understanding this demo: