Macintosh LC Developer Note
Download it here: Macintosh LC Developer Note.pdf
This is Apple Computer's own developer documentation for Macintosh LC, published in 1990. It covers the LC's 96-pin expansion connector, its signal definitions and its power budget, the video subsystem and monitor sense lines, and the sound subsystem.
Apple's developer notes are a different document from the Service Source repair manuals: the Service Source tells a technician which module to swap, while the developer note gives the electrical and architectural detail — rail currents, connector pinouts, power budgets and chip functions — that a repairer needs in order to make a go/no-go measurement. Several figures on this wiki are cited to this document.