Table of Contents
Programming Denise
Playfields
To display a playfield the bitplane pointers are set and the BPLEN
flag in DMACON
is set to TRUE
. The pointers are changed during display, so they must be reset at every vertical blanking or by a Copper instruction. To sez up a bitfield the following steps must be performed
- Load palette into color registers (
COLOR00
-COLOR32
) - Set resolution and interlace mode (
BPLCON0
) - Allocate the memory for bitplanes
- Set display window's size (
DIWSTRT
,DIWSTOP
) - Set data fetch pointers to allocated memory (
DDFSTRT
,DDFSTOP
) - Set modulo in order to map memory areas to the according display lines (
BPL1MOD
,BPL2MOD
) - Program Copper for redisplay
Denise's Registers
COLOR00 | 180 | word |
COLOR01 | 182 | word |
… | ||
COLOR31 | 1BE | word |
BPLCON | 100 | 3 words |
DIWSTRT | 08E | word |
DIWSTOP | 090 | word |
DDFSTRT | 092 | word |
DDFSTRT | 094 | word |
BPL1MOD | 108 | word |
BPL2MOD | 10A | word |