00 Port_StartButtonAndRegion
01 Port_SerialDataEXT
02 Port_SerialRaw
03 Port_SerialSend
04 Port_SerialReceive
05 Port_SerialStatus
06 Port_Stereo
3e Port_MemoryControl out
3f Port_IOPortControl out
7e Port_VCounter in
7f Port_PSG out
7f Port_HCounter in
be Port_VDPData
bf Port_VDPAddress out
bf Port_VDPStatus in
dc Port_IOPort1 in
dd Port_IOPort2 in