0x15 ( 21 )  Sprite and Layers System
  
BitsDescription
7Enable lores mode (soft reset = 0)
6Sprite priority (1 = sprite 0 on top, 0 = sprite 127 on top) (soft reset = 0)
5Enable sprite clipping in over border mode (soft reset = 0)
4:2Set layer priority (eg SLU = sprites over layer 2 over ula) (soft reset = 000) 000 - S L U 001 - L S U 010 - S U L 011 - L U S 100 - U S L 101 - U L S 110 - (U|T)S(T|U)(B+L) Blending layer and Layer 2 combined, colours clamped to [0,7] 111 - (U|T)S(T|U)(B+L-5) Blending layer and Layer 2 combined, colours clamped to [0,7]
1Enable sprites over border (soft reset = 0)
0Enable sprites (soft reset = 0)