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;; Common `reset` procedure for NROM "games". Check `basics/sprite.s` on
;; @mssola/NES for a proper explanation on the code (will be open soon,
;; promise!).
reset:
sei
cld
ldx #$40
stx $4017
ldx #$ff
txs
inx
stx $2000
stx $2001
stx $4010
@vblankwait1:
bit $2002
bpl @vblankwait1
ldx #0
lda #0
@ram_reset_loop:
sta $000, x
sta $100, x
sta $300, x
sta $400, x
sta $500, x
sta $600, x
sta $700, x
inx
bne @ram_reset_loop
lda #$ef
@sprite_reset_loop:
sta $200, x
inx
bne @sprite_reset_loop
lda #$00
sta $2003
lda #$02
sta $4014
@vblankwait2:
bit $2002
bpl @vblankwait2
lda #$3F
sta $2006
lda #$00
sta $2006
lda #$0F
ldx #$20
@palettes_reset_loop:
sta $2007
dex
bne @palettes_reset_loop
jmp main
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