IBM 5150 - Motherboard Diagrams
IBM's technical reference for the IBM 5150 contains a lot of diagrams.
Following are some motherboard related diagrams that I have created.
RAM bank layout
Reset flow
Clock generation
NMI generation
Data bus - Simplified
Address bus - Simplified
Speaker circuitry - Simplified
Cassette circuitry - Simplified
Dynamic RAM refresh
RAM parity generation and comparison
Keyboard interface circuitry
Generation of CS for U33 ROM
Some 8253 related circuitry
Transceiver between RAM banks and data bus
64KB-256KB motherboard - RAS and CAS Generation
16KB-64KB motherboard - Address bus to memory address bus
64KB-256KB motherboard - Address bus to memory address bus
Connection point for optional RUN LED