| RAOVR1, RAOVR0 | 18003AH | bits 11,10 | For rotation parameter A |
| RBOVR1, RBOVR0 | 18003AH | bits 15,14 | For rotation parameter B |
| RxOVR1 | RxOVR0 | Screen over processing |
| 0 | 0 | Repeat the image set in the display area outside the display area |
| 0 | 1 | Outside the display area, repeats the character pattern specified by the screen over pattern name register (Only when the rotary scroll screen is in cell format) |
| 1 | 0 | Make everything outside the display area transparent |
| 1 | 1 | Forcibly set the display area to 0 ≦ X regardless of the plane size or bitmap size <512, 0 ≦ Y <512, make all outside the area transparent |
If the rotary scroll screen is in bitmap format, do not set the process to repeat the character pattern specified in the screen over pattern name register.
When the rotary scroll screen is in bitmap format and the vertical size of the bitmap is 256 dots, the display area is forced to be 0 ≦ X <512, 0 ≦ Y <512, and the outside of the area is made transparent. If set, the same image will be displayed twice in 256 dots in the vertical direction.