=Technical information=
You can use the Port &F988 to read status 0 or select a page 0 registerPort &F888read/&F988 audio ports and the CRTC cursor registers write to program the raster interruption located at selected page 0 registerPort &0066. Both work on PlayCity and Play2CPC.???? to read status 1 or select a page 1 registerPort &???? read/write to the selected page 1 register
These audio ports are not sufficient to access You can also use the full potential of CRTC cursor registers to program the OPN3 soundchipraster interruption located at &0066. Another i/o address (unknown) is necessaryIt works both on PlayCity and on Play2CPC.
The OPN3 soundchip is mostly a light version of the OPNA soundchip with some functionalities removed: no external ADPCM, no Composite Sine Mode and no GPIO.
