Memory
Memory Map
| 0000 - 07FF | 2 KB RAM (or when 4 KB RAM is used until 0FFF) |
| 8000 - 81FF | Build in system ROM |
| 4001 | VP551 Supersound System: Set frequency channel C |
| 4002 | VP551 Supersound System: Set frequency channel D |
| 4003 | VP551 Supersound System: Set octave channel C or D |
| 4010 | VP551 Supersound System: Set amplitude channel C |
| 4020 | VP551 Supersound System: Set amplitude channel D |
| 8001 | VP550/VP551 Supersound System: Set frequency channel A |
| 8002 | VP550/VP551 Supersound System: Set frequency channel B |
| 8003 | VP550/VP551 Supersound System: Set octave channel A or B |
| 8010 | VP550/VP551 Supersound System: Set amplitude channel A |
| 8020 | VP550/VP551 Supersound System: Set amplitude channel B |
| 8030 | VP550/VP551 Supersound System: Enable interrupt |
| C000 - CFFF | VP590 Colour Board: Write colour RAM, low resolution |
| D000 - DFFF | VP590 Colour Board: Write colour RAM, high resolution |
During start-up the system ROM is also mapped to address 0000. The ROM will be swapped for RAM after the first OUT 4 instruction.