A collection of wires connecting the
CPU with
main memory that is used to identify particular locations (
addresses) in main memory. The width of the address bus (that is, the number of wires) determines how many unique
memory locations can be addressed. Modern
PCs and
Macintoshes have as many as 36 address lines, which enables them theoretically to
access 64
GB (gigabytes) of main memory. However, the actually amount of memory that can be accessed is usually much less than this theoretical limit due to chipset and motherboard limitations.
