•PCs have
four or five buses, each with different speeds, access methods, and protocols
•Buses
evolved around data path and speed
•So many
buses because single speed is not practical
•Buses
carry electrical power, control signals, memory addresses, and data
•On-board
ports (eg, keyboard port and mouse port)
•Expansion
slots can be located on motherboard; sometimes
stacked vertically on a second board