Manual Mode - Commodore Amiga Hardware Reference Manual

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 wili be from color registers 17-19. The color selection for the
higher numbered sprite will be from color registers 20, 24, and 28.
The following data structure is for the six-color spaceship made with two attached
sprites.
SPRITEO:
DC.W
DC.\V
DC.\V
DC.\V
DC.\V
DC.W
DC.\V
SPRITE1:
DC.W
DC.\V
DC.\V
DC.W
DC.W
DC.\V
DC.W
Manual Mode
$6D60,$7200
$OC30,$0000
$1818,$0420
$342C,$OE70
$1818,$0420
$OC30,$0000
$0000,$0000
$6D60,$7280
$07EO,$0000
$OFFO,$OOOO
$IFF8,$0000
$OFFO,$OOOO
$07EO,$OOOO
$0000,$0000
jVSTART = 65, HSTART = 128
jFirst color descriptor word
jEnd of sprite 0
;Same as sprite 0 except attach bit on
jFirst descriptor word for sprite 1
;End of sprite 1
It is almost always best to load sprites using the automatic DMA channels. Sometimes,
however, it is useful to load these registers directly from one of the microprocessors.
Sprites may be activated "manually" whenever they are not being used by a DMA chan-
nel. The same sprite that is showing a DMA-controlled icon near the top of the screen
can also be reloaded manually to show a vertical colored bar near the bottom of the
screen. Sprites can be activated manually even when the sprite DMA is turned off.
Sprite Hardware 119