diff --git a/audio/engine.asm b/audio/engine.asm
index a45f6564c..ddb20a986 100644
--- a/audio/engine.asm
+++ b/audio/engine.asm
@@ -16,27 +16,27 @@ SoundRestart: ; e8000
 	push bc
 	push af
 	call MusicOff
-	ld hl, $ff24 ; channel control registers
+	ld hl, rNR50 ; channel control registers
 	xor a
-	ld [hli], a ; ff24 ; volume/vin
-	ld [hli], a ; ff25 ; sfx channels
+	ld [hli], a ; rNR50 ; volume/vin
+	ld [hli], a ; rNR51 ; sfx channels
 	ld a, $80 ; all channels on
 	ld [hli], a ; ff26 ; music channels
 
-	ld hl, $ff10 ; sound channel registers
+	ld hl, rNR10 ; sound channel registers
 	ld e, $04 ; number of channels
 .clearsound
 ;   sound channel   1      2      3      4
 	xor a
-	ld [hli], a ; $ff10, $ff15, $ff1a, $ff1f ; sweep = 0
+	ld [hli], a ; rNR10, $ff15, rNR30, $ff1f ; sweep = 0
 
-	ld [hli], a ; $ff11, $ff16, $ff1b, $ff20 ; length/wavepattern = 0
+	ld [hli], a ; rNR11, rNR21, rNR31, rNR41 ; length/wavepattern = 0
 	ld a, $08
-	ld [hli], a ; $ff12, $ff17, $ff1c, $ff21 ; envelope = 0
+	ld [hli], a ; rNR12, rNR22, rNR32, rNR42 ; envelope = 0
 	xor a
-	ld [hli], a ; $ff13, $ff18, $ff1d, $ff22 ; frequency lo = 0
+	ld [hli], a ; rNR13, rNR23, rNR33, rNR43 ; frequency lo = 0
 	ld a, $80
-	ld [hli], a ; $ff14, $ff19, $ff1e, $ff23 ; restart sound (freq hi = 0)
+	ld [hli], a ; rNR14, rNR24, rNR34, rNR44 ; restart sound (freq hi = 0)
 	dec e
 	jr nz, .clearsound
 
@@ -208,10 +208,10 @@ UpdateSound: ; e805c
 	call FadeMusic
 	; write volume to hardware register
 	ld a, [Volume]
-	ld [$ff24], a
+	ld [rNR50], a
 	; write SO on/off to hardware register
 	ld a, [SoundOutput]
-	ld [$ff25], a
+	ld [rNR51], a
 	ret
 ; e8125
 
@@ -251,7 +251,7 @@ UpdateChannels: ; e8125
 	jr z, .asm_e8159
 	;
 	ld a, [SoundInput]
-	ld [$ff10], a
+	ld [rNR10], a
 .asm_e8159
 	bit 5, [hl] ; rest
 	jr nz, .ch1rest
@@ -264,48 +264,48 @@ UpdateChannels: ; e8125
 	jr .asm_e8175
 .asm_e816b
 	ld a, [$c294]
-	ld [$ff13], a
+	ld [rNR13], a
 	ld a, [$c295]
-	ld [$ff14], a
+	ld [rNR14], a
 .asm_e8175
 	bit 0, [hl]
 	ret z
 	ld a, [$c292]
 	ld d, a
-	ld a, [$ff11]
+	ld a, [rNR11]
 	and a, $3f ; sound length
 	or d
-	ld [$ff11], a
+	ld [rNR11], a
 	ret
 .asm_e8184
 	ld a, [$c292]
 	ld d, a
-	ld a, [$ff11]
+	ld a, [rNR11]
 	and a, $3f ; sound length
 	or d
-	ld [$ff11], a
+	ld [rNR11], a
 	ld a, [$c294]
-	ld [$ff13], a
+	ld [rNR13], a
 	ret
 .ch1rest
-	ld a, [$ff26]
+	ld a, [rNR52]
 	and a, %10001110 ; ch1 off
-	ld [$ff26], a
-	ld hl, $ff10
+	ld [rNR52], a
+	ld hl, rNR10
 	call ClearChannel
 	ret
 .asm_e81a2
 	ld hl, $c292
 	ld a, $3f ; sound length
 	or [hl]
-	ld [$ff11], a
+	ld [rNR11], a
 	ld a, [$c293]
-	ld [$ff12], a
+	ld [rNR12], a
 	ld a, [$c294]
-	ld [$ff13], a
+	ld [rNR13], a
 	ld a, [$c295]
 	or a, $80
-	ld [$ff14], a
+	ld [rNR14], a
 	ret
 
 .Channel2
@@ -322,31 +322,31 @@ UpdateChannels: ; e8125
 	ret z
 	ld a, [$c292]
 	ld d, a
-	ld a, [$ff16]
+	ld a, [rNR21]
 	and a, $3f ; sound length
 	or d
-	ld [$ff16], a
+	ld [rNR21], a
 	ret
 .asm_e81db ; unused
 	ld a, [$c294]
-	ld [$ff18], a
+	ld [rNR23], a
 	ld a, [$c295]
-	ld [$ff19], a
+	ld [rNR24], a
 	ret
 .asm_e81e6
 	ld a, [$c292]
 	ld d, a
-	ld a, [$ff16]
+	ld a, [rNR21]
 	and a, $3f ; sound length
 	or d
-	ld [$ff16], a
+	ld [rNR21], a
 	ld a, [$c294]
-	ld [$ff18], a
+	ld [rNR23], a
 	ret
 .ch2rest
-	ld a, [$ff26]
+	ld a, [rNR52]
 	and a, %10001101 ; ch2 off
-	ld [$ff26], a
+	ld [rNR52], a
 	ld hl, $ff15
 	call ClearChannel
 	ret
@@ -354,14 +354,14 @@ UpdateChannels: ; e8125
 	ld hl, $c292
 	ld a, $3f ; sound length
 	or [hl]
-	ld [$ff16], a
+	ld [rNR21], a
 	ld a, [$c293]
-	ld [$ff17], a
+	ld [rNR22], a
 	ld a, [$c294]
-	ld [$ff18], a
+	ld [rNR23], a
 	ld a, [$c295]
 	or a, $80 ; initial (restart)
-	ld [$ff19], a
+	ld [rNR24], a
 	ret
 
 .Channel3
@@ -377,34 +377,34 @@ UpdateChannels: ; e8125
 	ret
 .asm_e822f ; unused
 	ld a, [$c294]
-	ld [$ff1d], a
+	ld [rNR33], a
 	ld a, [$c295]
-	ld [$ff1e], a
+	ld [rNR34], a
 	ret
 .asm_e823a
 	ld a, [$c294]
-	ld [$ff1d], a
+	ld [rNR33], a
 	ret
 .ch3rest
-	ld a, [$ff26]
+	ld a, [rNR52]
 	and a, %10001011 ; ch3 off
-	ld [$ff26], a
-	ld hl, $ff1a
+	ld [rNR52], a
+	ld hl, rNR30
 	call ClearChannel
 	ret
 .asm_e824d
 	ld a, $3f
-	ld [$ff1b], a
+	ld [rNR31], a
 	xor a
-	ld [$ff1a], a
+	ld [rNR30], a
 	call .asm_e8268
 	ld a, $80
-	ld [$ff1a], a
+	ld [rNR30], a
 	ld a, [$c294]
-	ld [$ff1d], a
+	ld [rNR33], a
 	ld a, [$c295]
 	or a, $80
-	ld [$ff1e], a
+	ld [rNR34], a
 	ret
 .asm_e8268
 	push hl
@@ -458,7 +458,7 @@ UpdateChannels: ; e8125
 	ld a, [$c293]
 	and a, $f0
 	sla a
-	ld [$ff1c], a
+	ld [rNR32], a
 	ret
 
 .Channel4
@@ -472,24 +472,24 @@ UpdateChannels: ; e8125
 	ret
 .asm_e82c1 ; unused
 	ld a, [$c294]
-	ld [$ff22], a
+	ld [rNR43], a
 	ret
 .ch4rest
-	ld a, [$ff26]
+	ld a, [rNR52]
 	and a, %10000111 ; ch4 off
-	ld [$ff26], a
+	ld [rNR52], a
 	ld hl, $ff1f
 	call ClearChannel
 	ret
 .asm_e82d4
 	ld a, $3f ; sound length
-	ld [$ff20], a
+	ld [rNR41], a
 	ld a, [$c293]
-	ld [$ff21], a
+	ld [rNR42], a
 	ld a, [$c294]
-	ld [$ff22], a
+	ld [rNR43], a
 	ld a, $80
-	ld [$ff23], a
+	ld [rNR44], a
 	ret
 ; e82e7
 
@@ -535,15 +535,15 @@ Functione8307: ; e8307
 	ld hl, Tablee8350
 .updatehw
 	xor a
-	ld [$ff10], a ; sweep off
+	ld [rNR10], a ; sweep off
 	ld a, [hli]
-	ld [$ff11], a ; sound length / duty cycle
+	ld [rNR11], a ; sound length / duty cycle
 	ld a, [hli]
-	ld [$ff12], a ; ch1 volume envelope
+	ld [rNR12], a ; ch1 volume envelope
 	ld a, [hli]
-	ld [$ff13], a ; ch1 frequency lo
+	ld [rNR13], a ; ch1 frequency lo
 	ld a, [hli]
-	ld [$ff14], a ; ch1 frequency hi
+	ld [rNR14], a ; ch1 frequency hi
 .asm_e8335
 	ld a, d
 	inc a
@@ -1192,7 +1192,7 @@ ParseMusic: ; e85e1
 	jr nz, .ok
 	; ????
 	xor a
-	ld [$ff10], a ; sweep = 0
+	ld [rNR10], a ; sweep = 0
 .ok
 ; stop playing
 	; turn channel off
@@ -2454,56 +2454,56 @@ LoadSFX: ; e8c04
 	jr z, .ch6
 	res 0, [hl] ; turn it off
 	xor a
-	ld [$ff11], a ; length/wavepattern = 0
+	ld [rNR11], a ; length/wavepattern = 0
 	ld a, $08
-	ld [$ff12], a ; envelope = 0
+	ld [rNR12], a ; envelope = 0
 	xor a
-	ld [$ff13], a ; frequency lo = 0
+	ld [rNR13], a ; frequency lo = 0
 	ld a, $80
-	ld [$ff14], a ; restart sound (freq hi = 0)
+	ld [rNR14], a ; restart sound (freq hi = 0)
 	xor a
 	ld [SoundInput], a ; global sound off
-	ld [$ff10], a ; sweep = 0
+	ld [rNR10], a ; sweep = 0
 .ch6
 	ld hl, $c1fe ; ch6 on?
 	bit 0, [hl]
 	jr z, .ch7
 	res 0, [hl] ; turn it off
 	xor a
-	ld [$ff16], a ; length/wavepattern = 0
+	ld [rNR21], a ; length/wavepattern = 0
 	ld a, $08
-	ld [$ff17], a ; envelope = 0
+	ld [rNR22], a ; envelope = 0
 	xor a
-	ld [$ff18], a ; frequency lo = 0
+	ld [rNR23], a ; frequency lo = 0
 	ld a, $80
-	ld [$ff19], a ; restart sound (freq hi = 0)
+	ld [rNR24], a ; restart sound (freq hi = 0)
 .ch7
 	ld hl, $c230 ; ch7 on?
 	bit 0, [hl]
 	jr z, .ch8
 	res 0, [hl] ; turn it off
 	xor a
-	ld [$ff1a], a ; sound mode #3 off
-	ld [$ff1b], a ; length/wavepattern = 0
+	ld [rNR30], a ; sound mode #3 off
+	ld [rNR31], a ; length/wavepattern = 0
 	ld a, $08
-	ld [$ff1c], a ; envelope = 0
+	ld [rNR32], a ; envelope = 0
 	xor a
-	ld [$ff1d], a ; frequency lo = 0
+	ld [rNR33], a ; frequency lo = 0
 	ld a, $80
-	ld [$ff1e], a ; restart sound (freq hi = 0)
+	ld [rNR34], a ; restart sound (freq hi = 0)
 .ch8
 	ld hl, $c262 ; ch8 on?
 	bit 0, [hl]
 	jr z, .chscleared
 	res 0, [hl] ; turn it off
 	xor a
-	ld [$ff20], a ; length/wavepattern = 0
+	ld [rNR41], a ; length/wavepattern = 0
 	ld a, $08
-	ld [$ff21], a ; envelope = 0
+	ld [rNR42], a ; envelope = 0
 	xor a
-	ld [$ff22], a ; frequency lo = 0
+	ld [rNR43], a ; frequency lo = 0
 	ld a, $80
-	ld [$ff23], a ; restart sound (freq hi = 0)
+	ld [rNR44], a ; restart sound (freq hi = 0)
 	xor a
 	ld [NoiseSampleAddressLo], a
 	ld [NoiseSampleAddressHi], a
@@ -3126,13 +3126,13 @@ ChannelPointers: ; e8fd9
 ClearChannels: ; e8fe9
 ; runs ClearChannel for all 4 channels
 ; doesn't seem to be used, but functionally identical to SoundRestart
-	ld hl, $ff24
+	ld hl, rNR50
 	xor a
 	ld [hli], a
 	ld [hli], a
 	ld a, $80
 	ld [hli], a
-	ld hl, $ff10
+	ld hl, rNR10
 	ld e, $04
 .loop
 	call ClearChannel
@@ -3142,19 +3142,19 @@ ClearChannels: ; e8fe9
 ; e8ffe
 
 ClearChannel: ; e8ffe
-; input: hl = beginning hw sound register ($ff10, $ff15, $ff1a, $ff1f)
+; input: hl = beginning hw sound register (rNR10, $ff15, rNR30, $ff1f)
 ; output: 00 00 80 00 80
 
 ;   sound channel   1      2      3      4
 	xor a
-	ld [hli], a ; $ff10, $ff15, $ff1a, $ff1f ; sweep = 0
+	ld [hli], a ; rNR10, $ff15, rNR30, $ff1f ; sweep = 0
 
-	ld [hli], a ; $ff11, $ff16, $ff1b, $ff20 ; length/wavepattern = 0
+	ld [hli], a ; rNR11, rNR21, rNR31, rNR41 ; length/wavepattern = 0
 	ld a, $08
-	ld [hli], a ; $ff12, $ff17, $ff1c, $ff21 ; envelope = 0
+	ld [hli], a ; rNR12, rNR22, rNR32, rNR42 ; envelope = 0
 	xor a
-	ld [hli], a ; $ff13, $ff18, $ff1d, $ff22 ; frequency lo = 0
+	ld [hli], a ; rNR13, rNR23, rNR33, rNR43 ; frequency lo = 0
 	ld a, $80
-	ld [hli], a ; $ff14, $ff19, $ff1e, $ff23 ; restart sound (freq hi = 0)
+	ld [hli], a ; rNR14, rNR24, rNR34, rNR44 ; restart sound (freq hi = 0)
 	ret
 ; e900a
diff --git a/joypad.asm b/joypad.asm
index 2488ba1df..099bfbef6 100644
--- a/joypad.asm
+++ b/joypad.asm
@@ -40,10 +40,10 @@ Joypad: ; 935
 ; We can only get four inputs at a time.
 ; We take d-pad first for no particular reason.
 	ld a, D_PAD
-	ld [$ff00], a
+	ld [rJOYP], a
 ; Read twice to give the request time to take.
-	ld a, [$ff00]
-	ld a, [$ff00]
+	ld a, [rJOYP]
+	ld a, [rJOYP]
 	
 ; The Joypad register output is in the lo nybble (inversed).
 ; We make the hi nybble of our new container d-pad input.
@@ -57,14 +57,14 @@ Joypad: ; 935
 ; Buttons make 8 total inputs (A, B, Select, Start).
 ; We can fit this into one byte.
 	ld a, BUTTONS
-	ld [$ff00], a
+	ld [rJOYP], a
 ; Wait for input to stabilize.
-	ld a, [$ff00]
-	ld a, [$ff00]
-	ld a, [$ff00]
-	ld a, [$ff00]
-	ld a, [$ff00]
-	ld a, [$ff00]
+	ld a, [rJOYP]
+	ld a, [rJOYP]
+	ld a, [rJOYP]
+	ld a, [rJOYP]
+	ld a, [rJOYP]
+	ld a, [rJOYP]
 ; Buttons take the lo nybble.
 	cpl
 	and $f
@@ -73,7 +73,7 @@ Joypad: ; 935
 	
 ; Reset the joypad register since we're done with it.
 	ld a, $30
-	ld [$ff00], a
+	ld [rJOYP], a
 	
 ; To get the delta we xor the last frame's input with the new one.
 	ld a, [$ffa4] ; last frame
diff --git a/main.asm b/main.asm
index fd2a1965f..10c1a3c8d 100644
--- a/main.asm
+++ b/main.asm
@@ -150,47 +150,47 @@ DisableLCD: ; 568
 ; Most of this is just going through the motions
 
 ; don't need to do anything if lcd is already off
-	ld a, [$ff40] ; LCDC
+	ld a, [rLCDC]
 	bit 7, a ; lcd enable
 	ret z
 	
 ; reset ints
 	xor a
-	ld [$ff0f], a ; IF
+	ld [rIF], a
 	
 ; save enabled ints
-	ld a, [$ffff] ; IE
+	ld a, [rIE]
 	ld b, a
 	
 ; disable vblank
 	res 0, a ; vblank
-	ld [$ffff], a ; IE
+	ld [rIE], a
 	
 .wait
 ; wait until vblank
-	ld a, [$ff44] ; LY
+	ld a, [rLY]
 	cp 145 ; >144 (ensure beginning of vblank)
 	jr nz, .wait
 	
 ; turn lcd off
-	ld a, [$ff40] ; LCDC
+	ld a, [rLCDC]
 	and %01111111 ; lcd enable off
-	ld [$ff40], a ; LCDC
+	ld [rLCDC], a
 	
 ; reset ints
 	xor a
-	ld [$ff0f], a ; IF
+	ld [rIF], a
 	
 ; restore enabled ints
 	ld a, b
-	ld [$ffff], a ; IE
+	ld [rIE], a
 	ret
 ; 58a
 
 EnableLCD: ; 58a
-	ld a, [$ff40] ; LCDC
+	ld a, [rLCDC]
 	set 7, a ; lcd enable
-	ld [$ff40], a ; LCDC
+	ld [rLCDC], a
 	ret
 ; 591
 
@@ -822,18 +822,18 @@ UpdateCGBPals: ; c33
 	
 ForceUpdateCGBPals: ; c37
 ; save wram bank
-	ld a, [$ff70] ; wram bank
+	ld a, [rSVBK]
 	push af
 ; bankswitch
 	ld a, 5 ; BANK(BGPals)
-	ld [$ff70], a ; wram bank
+	ld [rSVBK], a
 ; get bg pal buffer
 	ld hl, BGPals ; 5:d080
 	
 ; update bg pals
 	ld a, %10000000 ; auto increment, index 0
-	ld [$ff68], a ; BGPI
-	ld c, $69 ; $ff69
+	ld [rBGPI], a
+	ld c, rBGPD - rJOYP
 	ld b, 4 ; NUM_PALS / 2
 	
 .bgp
@@ -878,8 +878,8 @@ ForceUpdateCGBPals: ; c37
 	
 ; update obj pals
 	ld a, %10000000 ; auto increment, index 0
-	ld [$ff6a], a
-	ld c, $6b ; $ff6b - $ff00
+	ld [rOBPI], a
+	ld c, rOBPD - rJOYP
 	ld b, 4 ; NUM_PALS / 2
 	
 .obp
@@ -922,7 +922,7 @@ ForceUpdateCGBPals: ; c37
 	
 ; restore wram bank
 	pop af
-	ld [$ff70], a ; wram bank
+	ld [rSVBK], a
 ; clear pal update queue
 	xor a
 	ld [$ffe5], a
@@ -936,7 +936,7 @@ DmgToCgbBGPals: ; c9f
 ; exists to forego reinserting cgb-converted image data
 
 ; input: a -> bgp
-	ld [$ff47], a ; bgp
+	ld [rBGP], a
 	push af
 	
 ; check cgb
@@ -958,7 +958,7 @@ DmgToCgbBGPals: ; c9f
 	ld hl, BGPals ; to
 	ld de, Unkn1Pals ; from
 ; order
-	ld a, [$ff47] ; bgp
+	ld a, [rBGP]
 	ld b, a
 ; # pals
 	ld c, 8 ; all pals
@@ -984,9 +984,9 @@ DmgToCgbObjPals: ; ccb
 ; input: d -> obp1
 ;		 e -> obp2
 	ld a, e
-	ld [$ff48], a ; obp0
+	ld [rOBP0], a
 	ld a, d
-	ld [$ff49], a ; obp1
+	ld [rOBP1], a
 	
 ; check cgb
 	ld a, [$ffe6]
@@ -1009,7 +1009,7 @@ DmgToCgbObjPals: ; ccb
 	; from
 	ld de, Unkn2Pals
 ; order
-	ld a, [$ff48] ; obp0
+	ld a, [rOBP0]
 	ld b, a
 ; # pals
 	ld c, 8 ; all pals
@@ -1137,7 +1137,7 @@ ClearTileMap: ; fc8
 	call ByteFill
 	
 ; We aren't done if the LCD is on
-	ld a, [$ff40] ; LCDC
+	ld a, [rLCDC]
 	bit 7, a
 	ret z
 	jp WaitBGMap
@@ -1427,7 +1427,7 @@ DMATransfer: ; 15d8
 	and a
 	ret z
 ; start transfer
-	ld [$ff55], a ; hdma5
+	ld [rHDMA5], a
 ; indicate that transfer has occurred
 	xor a
 	ld [$ffe8], a
@@ -1448,7 +1448,7 @@ UpdateBGMapBuffer: ; 15e3
 	and a
 	ret z
 ; save wram bank
-	ld a, [$ff4f] ; vram bank
+	ld a, [rVBK]
 	push af
 ; save sp
 	ld [$ffd9], sp
@@ -1471,7 +1471,7 @@ UpdateBGMapBuffer: ; 15e3
 	pop bc
 ; update palettes
 	ld a, $1
-	ld [$ff4f], a ; vram bank
+	ld [rVBK], a
 ; tile 1
 	ld a, [hli]
 	ld [bc], a
@@ -1482,7 +1482,7 @@ UpdateBGMapBuffer: ; 15e3
 	dec c
 ; update tiles
 	ld a, $0
-	ld [$ff4f], a ; vram bank
+	ld [rVBK], a
 ; tile 1
 	ld a, [de]
 	inc de
@@ -1499,7 +1499,7 @@ UpdateBGMapBuffer: ; 15e3
 	pop bc
 ; update palettes
 	ld a, $1
-	ld [$ff4f], a ; vram bank
+	ld [rVBK], a
 ; tile 1
 	ld a, [hli]
 	ld [bc], a
@@ -1510,7 +1510,7 @@ UpdateBGMapBuffer: ; 15e3
 	dec c
 ; update tiles
 	ld a, $0
-	ld [$ff4f], a ; vram bank
+	ld [rVBK], a
 ; tile 1
 	ld a, [de]
 	inc de
@@ -1540,7 +1540,7 @@ UpdateBGMapBuffer: ; 15e3
 	
 ; restore vram bank
 	pop af
-	ld [$ff4f], a ; vram bank
+	ld [rVBK], a
 	
 ; we don't need to update bg map until new tiles are loaded
 	xor a
@@ -1618,13 +1618,13 @@ UpdateBGMap: ; 164c
 .attr
 ; switch vram banks
 	ld a, 1
-	ld [$ff4f], a ; vram bank
+	ld [rVBK], a
 ; bg map 1
 	ld hl, AttrMap
 	call .getthird
 ; restore vram bank
 	ld a, 0
-	ld [$ff4f], a ; vram bank
+	ld [rVBK], a
 	ret
 	
 .tiles
@@ -1771,7 +1771,7 @@ SafeLoadTiles2: ; 170a
 	and a
 	ret z
 ; abort if too far into vblank
-	ld a, [$ff44] ; LY
+	ld a, [rLY]
 ; ly = 144-145?
 	cp 144
 	ret c
@@ -1873,7 +1873,7 @@ SafeLoadTiles: ; 1769
 	and a
 	ret z
 ; abort if too far into vblank
-	ld a, [$ff44] ; LY
+	ld a, [rLY]
 ; ly = 144-145?
 	cp 144
 	ret c
@@ -1989,7 +1989,7 @@ SafeTileAnimation: ; 17d3
 	ret z
 	
 ; abort if too far into vblank
-	ld a, [$ff44] ; LY
+	ld a, [rLY]
 ; ret unless ly = 144-150
 	cp 144
 	ret c
@@ -2003,24 +2003,24 @@ SafeTileAnimation: ; 17d3
 	ld a, BANK(DoTileAnimation)
 	rst Bankswitch ; bankswitch
 
-	ld a, [$ff70] ; wram bank
+	ld a, [rSVBK]
 	push af ; save wram bank
 	ld a, $1 ; wram bank 1
-	ld [$ff70], a ; wram bank
+	ld [rSVBK], a
 
-	ld a, [$ff4f] ; vram bank
+	ld a, [rVBK]
 	push af ; save vram bank
 	ld a, $0 ; vram bank 0
-	ld [$ff4f], a ; vram bank
+	ld [rVBK], a
 	
 ; take care of tile animation queue
 	call DoTileAnimation
 	
 ; restore affected banks
 	pop af
-	ld [$ff4f], a ; vram bank
+	ld [rVBK], a
 	pop af
-	ld [$ff70], a ; wram bank
+	ld [rSVBK], a
 	pop af
 	rst Bankswitch ; bankswitch
 	ret
@@ -2078,15 +2078,15 @@ AskSerial: ; 2063
 	
 ; handshake
 	ld a, $88
-	ld [$ff01], a
+	ld [rSB], a
 	
 ; switch to internal clock
 	ld a, %00000001
-	ld [$ff02], a
+	ld [rSC], a
 	
 ; start transfer
 	ld a, %10000001
-	ld [$ff02], a
+	ld [rSC], a
 	
 	ret
 ; 208a
@@ -2098,17 +2098,17 @@ GameTimer: ; 209e
 	nop
 	
 ; save wram bank
-	ld a, [$ff70] ; wram bank
+	ld a, [rSVBK]
 	push af
 	
 	ld a, $1
-	ld [$ff70], a ; wram bank
+	ld [rSVBK], a
 	
 	call UpdateGameTimer
 	
 ; restore wram bank
 	pop af
-	ld [$ff70], a ; wram bank
+	ld [rSVBK], a
 	ret
 ; 20ad
 
@@ -2523,13 +2523,13 @@ RNG: ; 2f8c
 
 	push bc
 ; Added value
-	ld a, [$ff04] ; divider
+	ld a, [rDIV]
 	ld b, a
 	ld a, [$ffe1]
 	adc b
 	ld [$ffe1], a
 ; Subtracted value
-	ld a, [$ff04] ; divider
+	ld a, [rDIV]
 	ld b, a
 	ld a, [$ffe2]
 	sbc b
@@ -2975,9 +2975,9 @@ ClearPalettes: ; 3317
 	
 ; In DMG mode, we can just change palettes to 0 (white)
 	xor a
-	ld [$ff47], a ; BGP
-	ld [$ff48], a ; OBP0
-	ld [$ff49], a ; OBP1
+	ld [rBGP], a
+	ld [rOBP0], a
+	ld [rOBP1], a
 	ret
 	
 .cgb
@@ -8827,11 +8827,11 @@ TimeOfDayPals: ; 8c011
 	ld hl, $d038 ; Unkn1Pals + 7 pals
 	
 ; save wram bank
-	ld a, [$ff70] ; wram bank
+	ld a, [rSVBK]
 	ld b, a
 ; wram bank 5
 	ld a, 5
-	ld [$ff70], a ; wram bank
+	ld [rSVBK], a
 	
 ; push palette
 	ld c, 4 ; NUM_PAL_COLORS
@@ -8846,7 +8846,7 @@ TimeOfDayPals: ; 8c011
 	
 ; restore wram bank
 	ld a, b
-	ld [$ff70], a ; wram bank
+	ld [rSVBK], a
 	
 	
 ; update sgb pals
@@ -8858,11 +8858,11 @@ TimeOfDayPals: ; 8c011
 	ld hl, $d03f ; last byte in Unkn1Pals
 	
 ; save wram bank
-	ld a, [$ff70] ; wram bank
+	ld a, [rSVBK]
 	ld d, a
 ; wram bank 5
 	ld a, 5
-	ld [$ff70], a ; wram bank
+	ld [rSVBK], a
 	
 ; pop palette
 	ld e, 4 ; NUM_PAL_COLORS
@@ -8877,7 +8877,7 @@ TimeOfDayPals: ; 8c011
 	
 ; restore wram bank
 	ld a, d
-	ld [$ff70], a ; wram bank
+	ld [rSVBK], a
 	
 ; update palettes
 	call UpdateTimePals
@@ -12683,7 +12683,7 @@ TitleScreen: ; 10ed67
 	
 ; VRAM bank 1
 	ld a, 1
-	ld [$ff4f], a
+	ld [rVBK], a
 	
 	
 ; Decompress running Suicune gfx
@@ -12756,7 +12756,7 @@ TitleScreen: ; 10ed67
 	
 ; Back to VRAM bank 0
 	ld a, $0
-	ld [$ff4f], a
+	ld [rVBK], a
 	
 	
 ; Decompress logo
@@ -12852,7 +12852,7 @@ TitleScreen: ; 10ed67
 	call ByteFill
 	
 ; Let LCD Stat know we're messing around with SCX
-	ld a, $43 ; ff43 ; SCX
+	ld a, rSCX - rJOYP
 	ld [$ffc6], a
 	
 ; Restore WRAM bank
@@ -12865,9 +12865,9 @@ TitleScreen: ; 10ed67
 	call $058a
 	
 ; Set sprite size to 8x16
-	ld a, [$ff40] ; LCDC
+	ld a, [rLCDC]
 	set 2, a
-	ld [$ff40], a ; LCDC
+	ld [rLCDC], a
 	
 ;
 	ld a, $70
diff --git a/vblank.asm b/vblank.asm
index 78d7151f0..8201c1e5c 100644
--- a/vblank.asm
+++ b/vblank.asm
@@ -69,13 +69,13 @@ VBlank0: ; 2b1
 	inc [hl]
 	
 ; advance rng
-	ld a, [$ff04] ; divider
+	ld a, [rDIV]
 	ld b, a
 	ld a, [$ffe1]
 	adc b
 	ld [$ffe1], a
 	
-	ld a, [$ff04] ; divider
+	ld a, [rDIV]
 	ld b, a
 	ld a, [$ffe2]
 	sbc b
@@ -87,16 +87,16 @@ VBlank0: ; 2b1
 	
 ; scroll x
 	ld a, [$ffcf]
-	ld [$ff43], a ; scx
+	ld [rSCX], a
 ; scroll y
 	ld a, [$ffd0]
-	ld [$ff42], a ; scy
+	ld [rSCY], a
 ; window y
 	ld a, [$ffd2]
-	ld [$ff4a], a ; wy
+	ld [rWY], a
 ; window x + 7
 	ld a, [$ffd1]
-	ld [$ff4b], a ; wx
+	ld [rWX], a
 	
 ; some time management is in order
 ; only have time for one of these during vblank
@@ -131,7 +131,7 @@ VBlank0: ; 2b1
 	call $ff80
 ;	403f:
 ;		ld a, $c4
-;		ld [$ff46], a ; oam dma
+;		ld [rDMA], a
 ;		ld a, $28
 ;	.loop
 ;		dec a
@@ -216,11 +216,11 @@ VBlank1: ; 337
 	
 ; scroll x
 	ld a, [$ffcf]
-	ld [$ff43], a ; scx
+	ld [rSCX], a
 	
 ; scroll y
 	ld a, [$ffd0]
-	ld [$ff42], a ; scy
+	ld [rSCY], a
 	
 ; time-sensitive fns
 	call UpdatePals
@@ -233,7 +233,7 @@ VBlank1: ; 337
 	call $ff80
 ;	403f:
 ;		ld a, $c4
-;		ld [$ff46], a ; oam dma
+;		ld [rDMA], a
 ;		ld a, $28
 ;	.loop
 ;		dec a
@@ -246,20 +246,20 @@ VBlank1: ; 337
 	ld [VBlankOccurred], a
 	
 ; get requested ints
-	ld a, [$ff0f] ; IF
+	ld a, [rIF]
 	ld b, a
 ; discard requested ints
 	xor a
-	ld [$ff0f], a ; IF
+	ld [rIF], a
 ; enable lcd stat
 	ld a, %10 ; lcd stat
-	ld [$ffff], a ; IE
+	ld [rIE], a
 ; rerequest serial int if applicable (still disabled)
 ; request lcd stat
 	ld a, b
 	and %1000 ; serial
 	or %10 ; lcd stat
-	ld [$ff0f], a ; IF
+	ld [rIF], a
 	
 	ei
 ; update sound
@@ -272,17 +272,17 @@ VBlank1: ; 337
 	di
 	
 ; get requested ints
-	ld a, [$ff0f] ; IF
+	ld a, [rIF]
 	ld b, a
 ; discard requested ints
 	xor a
-	ld [$ff0f], a ; IF
+	ld [rIF], a
 ; enable ints besides joypad
 	ld a, %1111 ; serial timer lcdstat vblank
-	ld [$ffff], a ; IE
+	ld [rIE], a
 ; rerequest ints
 	ld a, b
-	ld [$ff0f], a ; IF
+	ld [rIF], a
 	ret
 ; 37f
 
@@ -297,13 +297,13 @@ UpdatePals: ; 37f
 	
 ; update gb pals
 	ld a, [$cfc7]
-	ld [$ff47], a ; BGP
+	ld [rBGP], a
 	
 	ld a, [$cfc8]
-	ld [$ff48], a ; OBP0
+	ld [rOBP0], a
 	
 	ld a, [$cfc9]
-	ld [$ff49], a ; 0BP1
+	ld [rOBP1], a
 	
 	and a
 	ret
@@ -324,10 +324,10 @@ VBlank3: ; 396
 	
 ; scroll x
 	ld a, [$ffcf]
-	ld [$ff43], a ; scx
+	ld [rSCX], a
 ; scroll y
 	ld a, [$ffd0]
-	ld [$ff42], a ; scy
+	ld [rSCY], a
 	
 ; any pals to update?
 	ld a, [$ffe5]
@@ -342,7 +342,7 @@ VBlank3: ; 396
 	call $ff80
 ;	403f:
 ;		ld a, $c4 ; Sprites / $100
-;		ld [$ff46], a ; oam dma
+;		ld [rDMA], a
 ;		ld a, $28
 ;	.loop
 ;		dec a
@@ -355,15 +355,15 @@ VBlank3: ; 396
 	ld [VBlankOccurred], a
 	
 ; save int flag
-	ld a, [$ff0f] ; IF
+	ld a, [rIF]
 	push af
 ; reset ints
 	xor a
-	ld [$ff0f], a ; IF
+	ld [rIF], a
 ; force lcdstat int during sound update
 	ld a, %10 ; lcd stat
-	ld [$ffff], a ; IE
-	ld [$ff0f], a ; IF
+	ld [rIE], a
+	ld [rIF], a
 	
 	ei
 ; update sound
@@ -376,7 +376,7 @@ VBlank3: ; 396
 	di
 	
 ; request lcdstat
-	ld a, [$ff0f] ; IF
+	ld a, [rIF]
 	ld b, a
 ; and any other ints
 	pop af
@@ -384,13 +384,13 @@ VBlank3: ; 396
 	ld b, a
 ; reset ints
 	xor a
-	ld [$ff0f], a ; IF
+	ld [rIF], a
 ; enable ints besides joypad
 	ld a, %1111 ; serial timer lcdstat vblank
-	ld [$ffff], a ; IE
+	ld [rIE], a
 ; request ints
 	ld a, b
-	ld [$ff0f], a ; IF
+	ld [rIF], a
 	ret
 ; 3df
 
@@ -414,7 +414,7 @@ VBlank4: ; 3df
 	call $ff80
 ;	403f:
 ;		ld a, $c4
-;		ld [$ff46], a ; oam dma
+;		ld [rDMA], a
 ;		ld a, $28
 ;	.loop
 ;		dec a
@@ -456,7 +456,7 @@ VBlank5: ; 400
 	
 ; scroll x
 	ld a, [$ffcf]
-	ld [$ff43], a ; scx
+	ld [rSCX], a
 	
 ; if we can update pals, skip this part
 	call UpdatePalsIfCGB
@@ -475,12 +475,12 @@ VBlank5: ; 400
 	
 ; discard requested ints
 	xor a
-	ld [$ff0f], a ; IF
+	ld [rIF], a
 ; enable lcd stat
 	ld a, %10 ; lcd stat
-	ld [$ffff], a ; IE
+	ld [rIE], a
 ; request lcd stat
-	ld [$ff0f], a ; IF
+	ld [rIF], a
 	
 	ei
 ; update sound
@@ -494,10 +494,10 @@ VBlank5: ; 400
 	
 ; discard requested ints
 	xor a
-	ld [$ff0f], a ; IF
+	ld [rIF], a
 ; enable ints besides joypad
 	ld a, %1111 ; serial timer lcdstat vblank
-	ld [$ffff], a ; IE
+	ld [rIE], a
 	ret
 ; 436