To change the value of these registers, the register number should be output on address &BCxx and then the data output on &BDxx
| Reg | Function | Default Value | Reg | Function | Default Value | ||||
| R0 | Horizontal Total | 63 | R1 | Horizontal Displayed | 40 | ||||
| R2 | Horizontal Sync Pos. | 46 | R3 | Sync Width | 112 | ||||
| R4 | Vertical Total | 38 | R5 | Vertical Total Adjust | 0 | ||||
| R6 | Vertical Displayed | 25 | R7 | Vertical Sync Position | 30 | ||||
| R8 | Interlace and Skew | 0 | R9 | Maximum Raster Addr | 7 | ||||
| R10 | Cursor Start Raster | 0 | R11 | Cursor End Raster | 0 | ||||
| R12 | Start Address (H) | 48 | R13 | Start Address (L) | 0 | ||||
| R14 | Cursor Register (H) | 192 | R15 | Cursor Register (L) | 07 |