4000304h - NDS9 - POWCNT1 - Graphics Power Control Register (R/W)
0 Enable Flag for both LCDs (0=Disable) (Prohibited, see notes)
1 2D Graphics Engine A (0=Disable) (Ports 008h-05Fh, Pal 5000000h)
2 3D Rendering Engine (0=Disable) (Ports 320h-3FFh)
3 3D Geometry Engine (0=Disable) (Ports 400h-6FFh)
4-8 Not used
9 2D Graphics Engine B (0=Disable) (Ports 1008h-105Fh, Pal 5000400h)
10-14 Not used
15 Display Swap (0=Send Display A to Lower Screen, 1=To Upper Screen)
16-31 Not used
Use SwapBuffers command once after enabling Rendering/Geometry Engine.
Improper use of Bit0 may damage the hardware?
When disabled, corresponding Ports become Read-only, corresponding (palette-) memory becomes read-only-zero-filled.