200000-c00000 = main RAM

c00000-c80000 = GRP-16-1
c80000-d00000 = GRP-16-2
d00000-d80000 = GRP-16-3
d80000-e00000 = GRP-16-4

c00000-c80000 = GRP-256-1
c80000-d00000 = GRP-256-2

c00000-c80000 = GRP-65536

e00000-e20000 = text-r
e20000-e40000 = text-g
e40000-e60000 = text-b
e60000-e80000 = text-a

eb0000-eb0400 = sprite vram
eb8000-ec0000 = BG vram

f00000-f40000 = FONT rom


4-bpp linear sprites:
0-1 = xpos ($3ff)
2-3 = ypos ($3ff)
4-5 = v,h,pal,pcg ($cf / $ff)
6-7 = prw (0,1,2,3)

BG vram:
4-bpp linear, 512 pixels wide
8x8, 16x16 size

(note: BG shares with sprite characters)


text vram (TVRAM):
1-bpp planes (RGBA), 1024x1024 plane


GRP (3 modes)
- 4-bpp linear (512x512x4, 1024x1024)
- 8-bpp linear (512x512x2)
- 16-bpp linear (512x512)
