Macintosh IIfx Special Options and Technical Information
Download it here: Macintosh IIfx Special Options and Technical Information.pdf
This is Apple Computer's own developer documentation for Macintosh IIfx, published in 1990. It covers the IIfx's proprietary 64-pin SIMMs, its SCSI arrangement and termination requirements, and the options Apple offered on the machine. This copy is a scan and has no searchable text layer.
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.