diff --git a/Code/data.asm b/Code/data.asm
index efd8052..5f84162 100644
--- a/Code/data.asm
+++ b/Code/data.asm
@@ -23,7 +23,7 @@ BitsSet:
 EXPORT DefaultMap
 SECTION "Default Map", ROM0, ALIGN[8]
 DefaultMap:
-	; 32x18 map matching the startup nintendo logo
+	; 32x18 game of life map matching the startup nintendo logo
 	db 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 	db 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
 	db 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
diff --git a/Code/intro.asm b/Code/intro.asm
index 61e2141..7a73108 100644
--- a/Code/intro.asm
+++ b/Code/intro.asm
@@ -44,7 +44,8 @@ Intro:
 	jr z, .setBGPalette
 
 	; fade bg palette
-	ld b, 8
+FADE_DELAY = 8 ; frames
+	ld b, FADE_DELAY
 .fadeDelay0
 	HaltAndClearInterrupts
 	dec b
@@ -53,7 +54,7 @@ Intro:
 	ld a, %11111100
 	ldh [rBGP], a
 
-	ld b, 8
+	ld b, FADE_DELAY
 .fadeDelay1
 	HaltAndClearInterrupts
 	dec b
@@ -62,7 +63,7 @@ Intro:
 	ld a, %11111000
 	ldh [rBGP], a
 
-	ld b, 8
+	ld b, FADE_DELAY
 .fadeDelay2
 	HaltAndClearInterrupts
 	dec b
@@ -127,7 +128,7 @@ Intro:
 	ld a, LCDCF_ON | LCDCF_BGON | LCDCF_BG9800
 	ldh [rLCDC], a
 	
-	; sound
+	; sweep sound while transforming nintendo logo into game of life of it
 	ld a, $77
 	ldh [rNR10], a ; sweep 
 	ld a, (%00 << 6) + 0
@@ -146,22 +147,23 @@ FREQUENCY = 146
 	ld b, 20
 .loopX
 	ld c, 2
+	; 3 frame delay
 	HaltAndClearInterrupts
 	HaltAndClearInterrupts
 	HaltAndClearInterrupts
 .loopY
-	; copy 8 tiles (that's how many there is before L and E overflow)
+	; copy 8 tiles from (that's how many there is before L and E overflow)
 REPT 8
 	ld a, [hl]
 	ld [de], a
 	ld a, l
-	add a, $20
+	add a, SCRN_VX_B
 	ld l, a
 	ld a, e
-	add a, $20
+	add a, SCRN_VX_B
 	ld e, a
 ENDR
-	; L and E overflowed, we can increment H and L
+	; L and E overflowed, we can increment high byte of pointers (h and d)
 	inc h
 	inc d
 	dec c
@@ -171,10 +173,10 @@ REPT 2
 	ld a, [hl]
 	ld [de], a
 	ld a, l
-	add a, $20
+	add a, SCRN_VX_B
 	ld l, a
 	ld a, e
-	add a, $20
+	add a, SCRN_VX_B
 	ld e, a
 ENDR
 	; back to beginning (high byte)
@@ -187,10 +189,10 @@ ENDR
 	
 	; back to beginning + next column (low byte)
 	ld a, l
-	sub a, $3F
+	sub a, SCRN_VX_B * 2 - 1
 	ld l, a
 	ld a, e
-	sub a, $3F
+	sub a, SCRN_VX_B * 2 - 1
 	ld e, a
 	
 	dec b