Bit Plane Control Register (horizontal, scroll counter)
| Bit | Function | Description |
|---|---|---|
| 15 | X PF2H7 | [Not in reference manual] (PF2Hx =) Playfield 2 horizontal scroll code, x=0-7 |
| 14 | X PF2H6 | [Not in reference manual] |
| 13 | X PF2H1 | [Not in reference manual] |
| 12 | X PF2H0 | [Not in reference manual] |
| 11 | X PF1H7 | [Not in reference manual] (PF1Hx =) Playfield 1 horizontal scroll code, x=0-7 where PFyH0 = LSB = 35ns SHRES pixel (bits have been renamed, old PFyH0 now PFyH2, etc). Now that the scroll range has been quadrupled to allow for wider (32 or 64 bits) bitplanes. |
| 10 | X PF1H6 | [Not in reference manual] |
| 09 | X PF1H1 | [Not in reference manual] |
| 08 | X PF1H0 | [Not in reference manual] |
| 07 | PF2H5 | OCS/ECS |
| 06 | PF2H4 | " |
| 05 | PF2H3 | " |
| 04 | PF2H2 | " |
| 03 | PF1H5 | " |
| 02 | PF1H4 | " |
| 01 | PF1H3 | " |
| 00 | PF1H2 | " |