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;
; example.asm for TR8
;
.org 0
; address of the frame interrupt vector
.equ INT_VECT 0xff00
; setup an int handler so we
; can use the frame int to sync
ld a, >INT_VECT
ld x, <INT_VECT
ld b, <int_handler
ld [a : x], b
inc x
ld b, >int_handler
ld [a : x], b
; enable interrupts
cif
; loop filling the screen with one
; colour cycling the whole palette
ld b, 0
loop:
call fill
inc b
and b, 15
push b
call draw_sprite
pop b
; wait 1 second
ld x, 60
wait_loop:
halt
dec x
bnz
jmp wait_loop
jmp loop
; fill frame-buffer with a color in reg b
fill:
ld a, 0xbf
ld x, 0
ld y, 0x40
fill_loop:
ld [a : x], b
inc x
bno
jmp fill_loop
inc a
dec y
bnz
jmp fill_loop
ret
int_handler:
iret
draw_sprite:
; blitter in settings mode
ld x, 128
ld a, 0xb0
port a, x
; setup
inc a
; source
ld x, <sprite
port a, x
ld x, >sprite
port a, x
; destination (56, 56)
ld x, 56
port a, x
port a, x
; size 16x16
ld x, 16
port a, x
port a, x
; now blit
dec a
ld x, 3
; 3: write with transparent color support
port a, x
ret
sprite:
.incpng "assets/icon.png"
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