Programming Denise


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

  1. Load palette into color registers (COLOR00-COLOR32)
  2. Set resolution and interlace mode (BPLCON0)
  3. Allocate the memory for bitplanes
  4. Set display window's size (DIWSTRT, DIWSTOP)
  5. Set data fetch pointers to allocated memory (DDFSTRT, DDFSTOP)
  6. Set modulo in order to map memory areas to the according display lines (BPL1MOD, BPL2MOD)
  7. 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
hardware/denise_programming_model.txt · Last modified: 2010/03/09 10:37 by gilgamesh
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