Commodore Amiga A1000, Hardware Reference Manual

Page: 133 / 380

SUMMARY OF SPRITE REGISTERS
There are eight complete sets of registers used to describe the sprites. Each set consists
of five registers. Only the registers for sprite O are described here. All of the others are
the same, except for the name of the register, which includes the appropriate number.
POINTERS
Pointers are registers that are used by the system to point to the current data being used.
During screen display, the registers are incremented to point to the data being used as
the screen display progresses. Therefore, pointer registers must be freshly written during
the start of the vertical blanking period.
SPR0PTH and SPR0PTL
This pair of registers contains the 32-bit word address of Sprite 0 DMA data.
Pointer register names for the other sprites are:
SPR1PTH SPR1PTL
SPR2PTH SPR2PTL
SPR3PTH SPR3PTL
SPR4PTH SPR4PTL
SPRSPTH SPRSPTL
SPR6PTH SPR6PTL
SPR7PTH SPR7PTL
CONTROL REGISTERS
SPR0POS
This is the sprite 0 position register. The word written into this register controls the
position on the screen at which the upper left-hand corner of the sprite is to be placed.
The most significant bit of the first data word will be placed in this position on the screen.
- 124 Sprite Hardware -