#define RTG_MODE_ID 0x50FF1000UL
```
And the UAE config uses an 8-bit RTG screen:
```ini
gfx_width=864
gfx_height=486
gfx_colour_mode=32bit
gfxcard_type=ZorroIII
gfxcard_size=16
rtg_modes=0x3ffe
```
So the app opens a custom 8-bit Picasso96/uaegfx screen at `864x486`, using `BestModeID()` first, falling back to `0x50FF1000` if needed.