Hilaire Gagne: Anatomy of the 4040 Disk Drive
This book provides a complete description of the Commodore 4040 dual floppy drive. The book covers file management, data management disk management, file organization, advanced disk programming, hardware and software interfacing, RAM and ROM disassembly, and application examples.
The book contains a full commented disassembly of “CBM DOS V2.1” for the 4040. (The original source is available at https://github.com/mist64/cbmsrc.)
It was written with an unknown word processor, probably on a Commodore PET, and the original files were part of the estate of Dennis Jarvis.
The conversion tool and the HTML are tracked in a git repository.