Commodore Amiga A1000, Hardware Reference Manual

Page: 128 / 380

The binary numbers 0 through 15 select registers 17 through 31 as shown in Table 4-5.
Table 4-5: Color Registers in Attached Sprites
Decimal Binary ColorRegister
Number Number Number
0 0000 16 *
1 0001 17
2 0010 18
3 0011 19
4 0100 20
5 0101 21
6 0110 22
7 0111 23
8 1000 24
9 1001 25
10 1010 26
11 1011 27
12 1100 28
13 1101 29
14 lll0 30
15 1111 31
* Unused; yields transparent pixel.
Attachment is in effect only when the ATTACH bit, bit 7 in sprite control
word 2, is set to 1 in the data structure for the odd-numbered sprite. So,
in this example, you set bit 7 in sprite control word 2 in the data
structure for sprite 1.
When the sprites are moved, the Copper list must keep them both at exactly
the same position relative to each other. If they are not kept together on
the screen, their pixels will change color. Each sprite will revert to three
colors plus transparent, but the colors may be different than if they were
ordinary, unattached sprites. The color selection for the lower numbered
sprite will be from color registers 17-19. The color selection for the
higher numbered sprite will be from color registers 20, 24, and 28.
- Sprite Hardware 119 -