| | | 1. Does anybody know how the palette index and the palette starting adress are related, depending on the color mode ? |
The palette index make up the upper bits of the 11-bit address. The color RAM offset bits are added to the top bits of this value (color RAM mode 1 extends the address to 12 bits in the final step). See chapter 10 of the VDP2 manual. (Note that 24-bit colour palette entries are split between the two banks, see Charles MacDonald's technotes for an explanation.)
| | | 2. Do you know if it is possible to simultaneously have multiple palettes for sprites ? |
Yes, you use the CMDCOLR word to specify palette. |