Changes
This list shows only the internal standard I/O ports, as used in the BIOS ROM of the CPC 464/664/6128 BIOS, and in the AMSDOS ROM of the CPC 664/6128 and DDI-1. For a more complete list, including all Peripherals, see the [[I/O Port Summary|Complete I/O Port Summary]].
== Port Mapping ==
{|{{Prettytable|width: 700px; font-size: 2em;}}
|'''Hardware device'''||'''Address'''||'''Read/Write'''||'''b15'''||'''b14'''||'''b13'''||'''b12'''||'''b11'''||'''b10'''||'''b9'''||'''b8'''
|-
|Gate Array||&7F||Write Only||0||1||-||-||-||-||-||-
|-
|PAL||&7F||Write Only||0||-||-||-||-||-||-||-
|-
|CRTC||&BC-&BF||Read/Write||-||0||-||-||-||-||r1||r0
|-
|ROM select||&DF||Write Only||-||-||0||-||-||-||-||-
|-
|Printer port||&EF||Write Only||-||-||-||0||-||-||-||-
|-
|8255 PPI||&F4-&F7||Read/Write||-||-||-||-||0||-||r1||r0
|-
|Expansion devices||&F8-&FB||Read/Write||-||-||-||-||-||0||-||-
|}
0 means the bit must be set to 0 for the hardware device to respond, 1 means the bit must be set to 1 for the hardware device to respond, - means this bit is ignored. r1 and r0 mean a bit used to define a register
== I/O Ports ==
