01C0..01FF: 7FFFh Gate Array 3 (rambank, etc.)
0200..02FF: DFFFh Upper ROM Bank
0300..03FF: FFFFh FABFh Not used Ext Port (filled with incrementing values: 00h..FFh)
Part B (when MAPMOD=1)
0400..04FF: 5FFFh Not used (same as MAPMODE=0)
05C0..05FF: 7FFFh Gate Array 3 (rambank, etc.) (same as MAPMODE=0)
0600..06FF: DFFFh Upper ROM Bank (same as MAPMODE=0)
0700..07FF: FFFFh FABFh Not used Ext Port (same as MAPMODE=0)
Address 7FFFh: Gate Array 0: (A13=1, A15=0, DataIn=00h..3Fh) palette index