mirror of
https://frontier.innolan.net/github/AmigaExamples.git
synced 2026-09-13 04:35:01 +00:00
59 lines
1.5 KiB
ArmAsm
59 lines
1.5 KiB
ArmAsm
include "../include/registers.i"
|
|
include "hardware/dmabits.i"
|
|
include "hardware/intbits.i"
|
|
|
|
LVL3_INT_VECTOR equ $6c
|
|
SCREEN_WIDTH equ 320
|
|
SCREEN_HEIGHT equ 256
|
|
SCREEN_WIDTH_BYTES equ (SCREEN_WIDTH/8)
|
|
SCREEN_BIT_DEPTH equ 1
|
|
SCREEN_RES equ 8 ; 8=lo resolution, 4=hi resolution
|
|
RASTER_X_START equ $81 ; Hard coded coordinates from hardware manual
|
|
RASTER_Y_START equ $2c
|
|
RASTER_X_STOP equ RASTER_X_START+SCREEN_WIDTH
|
|
RASTER_Y_STOP equ RASTER_Y_START+SCREEN_HEIGHT
|
|
|
|
entry:
|
|
;; custom chip base globally in a6
|
|
lea CUSTOM,a6
|
|
|
|
;; poke bitplane pointers into the copper list
|
|
lea bitplane(pc),a0
|
|
lea copperBitPlanePtr(pc),a1
|
|
move.l a0,d0
|
|
move.w d0,6(a1) ;BPL1PTL
|
|
swap d0
|
|
move.w d0,2(a1) ;BPL1PTH
|
|
|
|
move.w #(RASTER_Y_START<<8)|RASTER_X_START,DIWSTRT(a6)
|
|
move.w #((RASTER_Y_STOP-256)<<8)|(RASTER_X_STOP-256),DIWSTOP(a6)
|
|
|
|
move.w #(RASTER_X_START/2-SCREEN_RES),DDFSTRT(a6)
|
|
move.w #(RASTER_X_START/2-SCREEN_RES)+(8*((SCREEN_WIDTH/16)-1)),DDFSTOP(a6)
|
|
|
|
move.w #(SCREEN_BIT_DEPTH<<12)|$200,BPLCON0(a6)
|
|
move.w #SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH-SCREEN_WIDTH_BYTES,BPL1MOD(a6)
|
|
|
|
;; install copper list and enable DMA
|
|
lea copper(pc),a0
|
|
move.l a0,COP1LC(a6)
|
|
move.w COPJMP1(a6),d0
|
|
move.w #(DMAF_SETCLR!DMAF_COPPER!DMAF_RASTER!DMAF_MASTER),dmacon(a6)
|
|
|
|
.mainLoop:
|
|
bra.b .mainLoop
|
|
|
|
copper:
|
|
copperBitPlanePtr:
|
|
dc.w BPL1PTH,0 ; address of the bitplane will be poked once we know it
|
|
dc.w BPL1PTL,0
|
|
|
|
dc.w COLOR00,$0000
|
|
|
|
include "out/copper-list.s"
|
|
|
|
dc.l $fffffffe
|
|
|
|
bitplane:
|
|
dcb.b (SCREEN_WIDTH*SCREEN_HEIGHT)/8,$00
|