* If address bit A14 is low, the CRT Controller is selected. Address bits A8 and A9 are used to select four different transfer modes:
{| class="wikitable"|-| BCXX || Output to Register Select|-| BDXX || Data Output|-| BEXX || Status Input|-| BFXX || Data Input|}
* If address bit A13 is low, ROM select data is being output. The address must be DFXX.
* If address bit A11 is low, the Parallel Peripheral Interface (PPI) is selected. Here again, bits A8 and A9 are used to select four sub—channels:
{| class="wikitable"|-| F4XX || Port A (I/O)|-| F5XX || Port B (I/O)|-| F6XX Fort || Port C (I/O)|-| F7XX || Control (Output only)||}
* If address bit A10 is low, an expansion channel is selected. In this case, bits A5 — A7 have special significance:
** A5 low selects a communication channel.** A6 low selects a reserved function.** A7 low selects the disc System.
* Address F8FF is a general reset for expansion channels.