2008ef8  -> 2006f70 -> 2006854 -> 200676c -> 20067b0
202a7a8 -> 202a8a8 -> 202aaa8 -> 02030AA8 -> 020362A8
0202A9F0

218B0
23838
23F54
24254
2A33C
2FAF8

02032FC8
02006798

XGB_SRAM	0, 0x800, 0x2000, 0x8000
XGB_VRAM	0x2000, 0x4000
GBC_EXRAM 	0x0000,0x6000
INSTANT PAGES    8 to 1024

examples:
zelda: 8192, 16384, 0, 256


X gain 0xC00 (3k) by removing font
X gain 0x1000 (4096) by sharing UI tilemap with a cache page (reload game data after leaving UI)
X gain 0x300 (768) by eating up top row of tileset

gain 0x2000 by eating sprite data (and probably moving sprites up 16384)
X gain 0x4000 by eating up CGB vram tiles
gain 0x1000 by dropping backtiles
