|'''Mem'''||'''Decoded as'''||'''Port'''||'''Read'''||'''Write'''
|-
|#4000-7FFF||%01xxxxxx xxxxxxxx||[[ASIC]] - CPC+/GX4000 registers|| Read || Write
|-
|}
The [[ASIC ]] I/O page is defined as follows:
{|{{Prettytable|width: 700px; font-size: 2em;}}