Hardware Documentation - Busses - ADB
Here are some links to information about the Apple Desktop Bus (ADB), as used in Apple Macintosh machines.
Primarily describes the Mac OS ADB Manager, but also how to communicate with devices on the ADB at a very low level.
Apple Technical Note explaining a number of esoteric and unknown issues concerning the Apple Desktop Bus.
Archived Apple Q&As relating to the ADB bus. Mainly Mac OS specific.