Editing MOS Technology 6510 (section)

==Use==
In the C64, the extra I/O pins of the processor are used to control the computer's [[memory map]] by [[bank switching]], and for controlling three of the four signal lines of the [[Commodore Datasette|Datasette]] tape recorder (the electric motor control, key-press sensing and write data lines; the read data line went to another I/O chip).  It is possible, by writing the correct [[bit pattern]] to the processor at address $01, to completely expose almost the full 64&nbsp;[[kilobyte|KB]] of [[Random-access memory|RAM]] in the C64, leaving no [[Read-only memory|ROM]] or [[I/O]] hardware exposed except for the processor I/O port itself and its data directional register at address $00.<ref>{{cite magazine |url=http://www.atarimagazines.com/compute/issue32/112_1_COMMODORE_64_ARCHITECTURE.php |title=Commodore 64 Architecture |first=Jim|last=Butterfield |magazine=Compute! |date=January 1983 |page=208 |issue=32}}</ref>