* Port &F984 to read status 1 or select a page 1 register
* Port &F884 read/write to the selected page 1 register
The SSG, the digidrums and the first 3 FM chans are accessed on register page 0. The last 3 FM chans are accessed on register page 1.
You can also use the CRTC cursor registers to program the raster interruption located at &0066.