Equivalents to 6502 instructions

Many new Game Boy programmers have experience on a platform with a 6502 family (6502, 6507, 6510, 65C02, 65816, or HuC6280) processor. These include Apple II, Atari 8-bit (2600 VCS, 800, 5200, 7800 ProSystem, Lynx), Nintendo (NES/Famicom, Super NES/Super Famicom), and TurboGrafx-16/PC Engine. To help these programmers adapt, this table lists the closest opcode in the Game Boy CPU to each instruction in a WDC/Rockwell 65C02 CPU.

65C02 instruction	SM83 instruction	Notes
adc	adc	See also add
and	and	Clears carry
asl	sla, add a	It always stood for Add to SeLf
bbr	bit then jr z
bbs	bit then jr nz
bcc	jr nc
bcs	jr c
beq	jr z
bit	bit	Tests the argument against a given bit, not the bits set in A
bmi	bit 7 then jr nz
bne	jr nz
bpl	bit 7 then jr z	If using to test a counter for wrapping from $00 to $FF, dec b then jr nz is more commonly used.
bra	jr
brk	rst
bvc	No direct equivalent	Replacement uses xor and bit 7
bvs	No direct equivalent
clc	scf then ccf	or a also clears Z. Less needed in general because add exists.
cld	No direct equivalent	Skip daa after add or sub
cli	ei	Also enables vblank if set in LCDC, as Game Boy does not use NMI
clv	No direct equivalent	No SO pin. If using with bvc to simulate bra, use jr without a condition.
cmp	cp	Carry sense is inverted
cpx	No direct equivalent	Load a value into A and compare it to B, C, etc.
cpy	No direct equivalent
dec	dec
dex	dec b
dey	dec c
eor	xor	Clears carry
inc	inc
inx	inc b
iny	inc c
jmp	jp	Can be made conditional
jsr	call
lda	ld a	Does not change Z
ldx	ld b	Does not change Z; accessing arrays is very different
ldy	ld c
lsr	srl	See also sra which copies bit 7 to carry first
nop	nop
ora	or	Clears carry
pha	push af	Only pairs of registers can be pushed or popped. BC, DE, and HL are more commonly pushed or popped.
php	push af
phx	push bc
phy	push bc
pla	pop af
plp	pop af
plx	pop bc
ply	pop bc
rol	rla, rl, adc a	See also rlc which copies bit 7 to carry first
rmb	res
ror	rra, rr	See also rrc which copies bit 0 to carry first
rti	pop af then reti	Interrupt handlers do not automatically push flags.
rts	ret	Can be made conditional. See also jp hl
sbc	sbc	Carry sense is inverted; see also sub
sec	scf
sed	No direct equivalent	Use daa after add or sub
sei	di	Disables vblank, as Game Boy does not use NMI
smb	set
sta	ld [destination],a
stx	ld [hl], b	There are two main ways for data to get in and out of registers: through A or through [HL].
sty	ld [hl], c
stz	xor a then ld [destination],a	Sets Z, clears carry and A
tax	ld b, a	Does not change Z
tay	ld c, a	Does not change Z
trb	res place, [hl]
tsb	set place, [hl]
tsx	ld hl, sp+0	Does not change Z
txa	ld a, b	Does not change Z
txs	ld sp, hl
tya	ld a, c	Does not change Z
wai	halt