Commodore Amiga A1000 Hardware Reference Manual page 94

Bit 8 - GAUD (genlock audio enable)
1 = Genlock audio enabled
0 = Genlock audio disabled (in blanking periods, this bit goes out
on the pixel switch
Bit 9 - COLOR ON (color enable)
1 = composite video color-burst enabled
0 = composite video color-burst disabled
Bit 10 - DBLPF (double-playfield enable)
1 = dual playfields enabled
0 = single playfield enabled
Bit 11 - HOMOD (hold-and-modify enable)
1 = hold-and-modify enabled
0 = hold-and-modify disabled
Bits 14, 13,12 - BPU2, BPU1, BPU0
Number of bit-planes used.
000 = only a background color
001 = 1 bit-plane, PLANE 1
010 = 2 bit-planes, PLANES 1 and 2
011 = 3 bit-planes, PLANES 1- 3
100 = 4 bit-planes, PLANES 1- 4
101 = 5 bit-planes, PLANES 1- 5
110 = 6 bit-planes, PLANES 1- 6
111 not used
Bit 15 - HIRES (high-resolution enable)
1 = high-resolution mode
0 = low-resolution mode
BPLCON1 - Bit-plane Control
Bits 3-0 - PF1H(3-0)
Playfield 1 delay
Bits 7-4 - PF2H(3-0)
Playfield 2 delay
Bits 15-8 not used
- Playfield Hardware 85 -