Different songs EVERYWHERE [Sonic 1 / Hivebrain 2006]

So, some years ago I came up with a very rudimentary implementation of "different songs in different acts" for Sonic 1, and I did the mistake to post it as it was; I later refined it a lot for my own hack, and I never went back to post the improved version. I'll do that now. With this guide you will be able to have:

• a different song in each act of each zone;
• a different song for each boss;
• a different song for each special stage;
• a different song for the good and bad credits;
• a different song for the good and bad mini-GHZ at the end;
• a different song for each note monitor (actually let's scrap this point since you don't have them in your hack);
• it also implies that you use a song for the Speed Shoes rather than the default speed-up, and it allows you to have an even different song for Invincibility + Speed Shoes at the same time (either obtained by a working "S" monitor or simply by collecting an Invincibility monitor and a Speed Shoes monitor within the time limits);
• it will also fix the bug with drowning countdown and invincibility music in Labyrinth Zone as a side effect.

Before you follow this guide, I highly recommend you to apply one of the methods which allow you to have more song slots, or you'll run into a paradox where you can choose different songs but you don't actually have them available. I won't recommend you to make a backup, because if you aren't smart enough to make a backup without me telling you to do so you deserve to lose all your work and suffer eternal pain. And yes, I like to write words in italics for no reason at all.

One last note: you can't apply this guide on top of the previous one, since I didn't keep track of the differences between them, so I'll be writing this by comparing the soniNeko disassembly with a clean one in real time while I type it, and I hope I can find all the things to edit, since I did this 5 years ago and I forgot many things. My fault for being lazy back then.


Summary:

• Step 1: we have more playlists now!
• Step 2: the Level_GetBgm routine
• Step 3: Invincibility and Speed Shoes
• Step 4: the Boss music
• Step 5: «oh fuck oh fuck air bubble air bubble»
• Step 6: Special Stages
• Step 7: ending and credits
• Step 8: set up the new playlists

I'm sorry if I made multiple posts in a row, but IPB is retarded and it likes to destroy CODE boxes when an edit is made, so I preferred to work on smaller posts.

 

Step 1: we have more playlists now!


Find:

; ---------------------------------------------------------------------------
; Music to play after invincibility wears off
; ---------------------------------------------------------------------------
MusicList2: incbin miscmuslist2.bin
even
; ===========================================================================
And delete it.

Find:

Code:

; ---------------------------------------------------------------------------
; Music	playlist
; ---------------------------------------------------------------------------
MusicList:	incbin	miscmuslist1.bin
		even
; ===========================================================================

And change it to:

Code:

; ---------------------------------------------------------------------------
; Music	playlist
; ---------------------------------------------------------------------------
MusicList1:	incbin	soundmuslist1.bin
		even
MusicList2:	incbin	soundmuslist2.bin
		even
MusicList3:	incbin	soundmuslist3.bin
		even
MusicList4:	incbin	soundmuslist4.bin
		even
MusicList5:	incbin	soundmuslist5.bin
		even
MusicList6:	incbin	soundmuslist6.bin
		even
MusicList7:	incbin	soundmuslist7.bin
		even
MusicList8:	incbin	soundmuslist8.bin
		even
; ===========================================================================

The first 4 playlists will now refer to the 4 acts of each zone; 5 is for the Special Stages, 6 is for the Credits, 7 is for the mini-GHZ ending, 8 is for the bosses. I have a 9th playlist in my hack, but as I said I'm not going to cover note monitors here since you don't have them.

 

Step 2: the Level_GetBgm routine


Find:

Code:

Level_GetBgm:
		tst.w	($FFFFFFF0).w
		bmi.s	loc_3946
		moveq	#0,d0
		move.b	($FFFFFE10).w,d0
		cmpi.w	#$103,($FFFFFE10).w ; is level SBZ3?
		bne.s	Level_BgmNotLZ4	; if not, branch
		moveq	#5,d0		; move 5 to d0

Level_BgmNotLZ4:
		cmpi.w	#$502,($FFFFFE10).w ; is level FZ?
		bne.s	Level_PlayBgm	; if not, branch
		moveq	#6,d0		; move 6 to d0

Level_PlayBgm:
		lea	(MusicList).l,a1 ; load	music playlist
		move.b	(a1,d0.w),d0	; add d0 to a1
		bsr.w	PlaySound	; play music
		move.b	#$34,($FFFFD080).w ; load title	card object

Replace it with:

Code:

Level_GetBgm:
		tst.w	($FFFFFFF0).w
		bmi.w	loc_3946		; change bmi.s to bmi.w or it won't work!
		moveq	#0,d0
		move.b	($FFFFFE10).w,d0

		cmpi.b	#$0,($FFFFFE11).w	; is this act 1?
		bne.s	Level_GetBgm2	; if not, branch
		lea	(MusicList1).l,a1	; load Music Playlist for Acts 1
		bra.s	Level_PlayBgm	; go to PlayBgm

Level_GetBgm2:
		cmpi.b	#$1,($FFFFFE11).w	; is this act 2?
		bne.s	Level_GetBgm3	; if not, branch
		lea	(MusicList2).l,a1	; load Music Playlist for Acts 2
		bra.s	Level_PlayBgm	; go to PlayBgm

Level_GetBgm3:
		cmpi.b	#$2,($FFFFFE11).w	; is this act 3?
		bne.s	Level_GetBgm4	; if not, branch
		lea	(MusicList3).l,a1	; load Music Playlist for Acts 3
		bra.s	Level_PlayBgm	; go to PlayBgm

Level_GetBgm4:
		lea	(MusicList4).l,a1	; load Music Playlist for Acts 4

Level_PlayBgm:
		move.b	(a1,d0.w),d0	; get d0-th entry from the playlist
		move.b	d0,($FFFFFFFE).w	; put music number in RAM for later use
		bsr.w	PlaySound	; play music
		move.b	#$34,($FFFFD080).w ; load title	card object

The comments are a bit outdated, now I know what lea actually does. It loads the address of a particular music list, and then d0 is used to pick the correct entry. This code is quite simple and it looks almost like the old version, but there's a new thing: look at this line:

Code:

move.b	d0,($FFFFFFFE).w	; put music number in RAM for later use

In this way, the song being currently played is stored in a RAM address. $FFFFFFFE is usually usable since it's only used for the checksum check and never touched again.

 

Step 3: Invincibility and Speed Shoes


Find:

Obj2E_ChkShoes:
cmpi.b #3,d0 ; does monitor contain speed shoes?
bne.s Obj2E_ChkShield
move.b #1,($FFFFFE2E).w ; speed up the BG music
move.w #$4B0,($FFFFD034).w ; time limit for the power-up
move.w #$C00,($FFFFF760).w ; change Sonic's top speed
move.w #$18,($FFFFF762).w
move.w #$80,($FFFFF764).w
move.w #$E2,d0
jmp (PlaySound).l ; Speed up the music
; ===========================================================================Replace it with:

Code:

Obj2E_ChkShoes:
		cmpi.b	#3,d0		; does monitor contain speed shoes?
		bne.s	Obj2E_ChkShield
		move.w	#$4B0,($FFFFD034).w ; time limit for the power-up

		cmpi.b	#$1,($FFFFFE2E).w	; am I already speed shoe'd?
		beq.s	Obj2E_NoMusic2	; if so, branch

		move.b	#1,($FFFFFE2E).w ; speed up the	BG music
		move.w	#$C00,($FFFFF760).w ; change Sonic's top speed
		move.w	#$18,($FFFFF762).w
		move.w	#$80,($FFFFF764).w

		cmpi.b	#$1,($FFFFFE2D).w	; do I also have invincibility?
		bne.b	Obj2E_spd_only	; if I don't then play regular speed shoes music
		move.w	#$F2,d0		; if I do, then play awesome music
		bra.b	Obj2E_spd_play
Obj2E_spd_only:
		move.w	#$FB,d0
Obj2E_spd_play:
		jmp	(PlaySound).l	; Speed	up the music
; ===========================================================================
Obj2E_NoMusic2:
		rts

Please note that there are two things to edit here: $FB is the song I used for the Speed Shoes, but you're likely to want to use a different ID there; likewise, $F2 is the song I used for Speed Shoes + Invincibility, but maybe you don't even have that one. Note the nice Obj2E_NoMusic2 label: in this way, if you collect another monitor with Speed Shoes while the first one didn't wear off yet, the music won't restart playing, but it will simply keep on playing, with the Speed Shoes timer reset to 20 seconds (yes, reset to, not increased by; you can change this behaviour by fiddling with a specific move.w, I won't tell you how, anyway).

Now, find:

Obj2E_ChkInvinc:
cmpi.b #5,d0 ; does monitor contain invincibility?
bne.s Obj2E_ChkRings
move.b #1,($FFFFFE2D).w ; make Sonic invincible
move.w #$4B0,($FFFFD032).w ; time limit for the power-up
move.b #$38,($FFFFD200).w ; load stars object ($3801)
move.b #1,($FFFFD21C).w
move.b #$38,($FFFFD240).w ; load stars object ($3802)
move.b #2,($FFFFD25C).w
move.b #$38,($FFFFD280).w ; load stars object ($3803)
move.b #3,($FFFFD29C).w
move.b #$38,($FFFFD2C0).w ; load stars object ($3804)
move.b #4,($FFFFD2DC).w
tst.b ($FFFFF7AA).w ; is boss mode on?
bne.s Obj2E_NoMusic ; if yes, branch
move.w #$87,d0
jmp (PlaySound).l ; play invincibility music
; ===========================================================================Replace it with:

Code:

Obj2E_ChkInvinc:
		cmpi.b	#5,d0		; does monitor contain invincibility?
		bne.w	Obj2E_ChkRings
		move.w	#$4B0,($FFFFD032).w ; time limit for the power-up

		cmpi.b	#$1,($FFFFFE2D).w	; am I already invincible?
		beq.s	Obj2E_NoMusic	; if so, branch

		move.b	#1,($FFFFFE2D).w ; make	Sonic invincible

		move.b	#$38,($FFFFD200).w ; load stars	object ($3801)
		move.b	#1,($FFFFD21C).w
		move.b	#$38,($FFFFD240).w ; load stars	object ($3802)
		move.b	#2,($FFFFD25C).w
		move.b	#$38,($FFFFD280).w ; load stars	object ($3803)
		move.b	#3,($FFFFD29C).w
		move.b	#$38,($FFFFD2C0).w ; load stars	object ($3804)
		move.b	#4,($FFFFD2DC).w
		tst.b	($FFFFF7AA).w	; is boss mode on?
		bne.s	Obj2E_NoMusic	; if yes, branch

		cmpi.b	#$1,($FFFFFE10).w	; is this Labyrinth?
		bne.s	NotLZinv	; if not, branch
		move.w	($FFFFFE14).w,d0 ; check air remaining
		cmpi.w	#$C,d0
		bhi.s	NotLZinv	; if air is above $C, branch
		bra.s	Obj2E_NoMusic

NotLZinv:
		cmpi.b	#$1,($FFFFFE2E).w	; do I also have speed shoes?
		bne.b	Obj2E_inv_only	; if I don't then play regular invincibility music
		move.w	#$F2,d0		; if I do, then play awesome music
		bra.b	Obj2E_inv_play
Obj2E_inv_only:
		move.w	#$87,d0
Obj2E_inv_play:
		jmp	(PlaySound).l	; play invincibility music
; ===========================================================================

Things to note:

• like the Speed Shoes, this code will keep on playing the Invincibility music if you collect a second monitor while the first one isn't worn off yet (it's easy to test that in GHZ1, for example);
• it won't start the invincibility music if your air is below $C (e.g. the countdown jingle is playing);
• $87 is the music ID for Invincibility only, and $F2 is still the music ID for Invincibility + Speed Shoes: fix those IDs accordingly.

Now, let's take care of them when they wear off, shall we?


Find:

Code:

Obj01_ChkInvin:
		tst.b	($FFFFFE2D).w	; does Sonic have invincibility?
		beq.s	Obj01_ChkShoes	; if not, branch
		tst.w	$32(a0)		; check	time remaining for invinciblity
		beq.s	Obj01_ChkShoes	; if no	time remains, branch
		subq.w	#1,$32(a0)	; subtract 1 from time
		bne.s	Obj01_ChkShoes
		tst.b	($FFFFF7AA).w
		bne.s	Obj01_RmvInvin
		cmpi.w	#$C,($FFFFFE14).w
		bcs.s	Obj01_RmvInvin
		moveq	#0,d0
		move.b	($FFFFFE10).w,d0
		cmpi.w	#$103,($FFFFFE10).w ; check if level is	SBZ3
		bne.s	Obj01_PlayMusic
		moveq	#5,d0		; play SBZ music

Obj01_PlayMusic:
		lea	(MusicList2).l,a1
		move.b	(a1,d0.w),d0
		jsr	(PlaySound).l	; play normal music

Obj01_RmvInvin:
		move.b	#0,($FFFFFE2D).w ; cancel invincibility

Obj01_ChkShoes:
		tst.b	($FFFFFE2E).w	; does Sonic have speed	shoes?
		beq.s	Obj01_ExitChk	; if not, branch
		tst.w	$34(a0)		; check	time remaining
		beq.s	Obj01_ExitChk
		subq.w	#1,$34(a0)	; subtract 1 from time
		bne.s	Obj01_ExitChk
		move.w	#$600,($FFFFF760).w ; restore Sonic's speed
		move.w	#$C,($FFFFF762).w ; restore Sonic's acceleration
		move.w	#$80,($FFFFF764).w ; restore Sonic's deceleration
		move.b	#0,($FFFFFE2E).w ; cancel speed	shoes
		move.w	#$E3,d0
		jmp	(PlaySound).l	; run music at normal speed
; ===========================================================================

Obj01_ExitChk:
		rts

Replace it with:

Code:

Obj01_ChkInvin:
		tst.b	($FFFFFE2D).w	; does Sonic have invincibility?
		beq.s	Obj01_ChkShoes	; if not, branch
		tst.w	$32(a0)		; check	time remaining for invinciblity
		beq.s	Obj01_ChkShoes	; if no	time remains, branch
		subq.w	#1,$32(a0)	; subtract 1 from time
		bne.b	Obj01_ChkShoes
		cmpi.b	#$1,($FFFFFFFF).w	; boss
		beq.b	Obj01_RmvInvin
		cmpi.w	#$C,($FFFFFE14).w	; underwater
		bcs.b	Obj01_RmvInvin

		cmpi.b	#$1,($FFFFFE2E).w	; does Sonic have speed shoes?
		bne.s	Obj01_Load_inv	; if no, branch, and load regular stage music
		move.b	#$FB,d0		; if yes, load regular speed shoes music
		bra.b	Obj01_Play_inv
Obj01_Load_inv
		move.b	$FFFFFFFE,d0	; loads song number from RAM
Obj01_Play_inv:
		jsr	(PlaySound).l	; play normal music

Obj01_RmvInvin:
		move.b	#0,($FFFFFE2D).w ; cancel invincibility

Obj01_ChkShoes:
		tst.b	($FFFFFE2E).w	; does Sonic have speed	shoes?
		beq.s	Obj01_ExitChk	; if not, branch
		tst.w	$34(a0)		; check	time remaining
		beq.s	Obj01_ExitChk
		subq.w	#1,$34(a0)	; subtract 1 from time
		bne.s	Obj01_ExitChk
		move.w	#$600,($FFFFF760).w ; restore Sonic's speed
		move.w	#$C,($FFFFF762).w ; restore Sonic's acceleration
		move.w	#$80,($FFFFF764).w ; restore Sonic's deceleration
		move.b	#0,($FFFFFE2E).w ; cancel speed	shoes

		cmpi.b	#$1,($FFFFFFFF).w	; boss
		beq.b	Obj01_ExitChk

		cmpi.b	#$1,($FFFFFE2D).w	; does Sonic have invincibility?
		bne.s	Obj01_Load_spd	; if no, branch, and load regular stage music
		move.b	#$87,d0		; if yes, load regular invincibility music
		bra.b	Obj01_Play_spd
Obj01_Load_spd:
		move.b	$FFFFFFFE,d0	; loads song number from RAM
Obj01_Play_spd:
		jmp	(PlaySound).l	; run music at normal speed
; ===========================================================================

Obj01_ExitChk:
		rts

The new code is quite more complex, as it takes more cases into account. Please note that $F2 and $87 are still the separate song IDs for Speed Shoes and Invincibility respectively, so you'll have to change them. Note the introduction of a new RAM address, $FFFFFFFF, which is used to store a boss flag (I'll explain that soon). Also note how $FFFFFFFE is used, avoiding the need to redo all those zone/act checks. I will handle the ResumeMusic routine (the one used when the drowning music is canceled) in a later step.

 

Step 4: the Boss music


Ok, this is boring. Find the FIVE instances of:


move.w #$8C,d0
bsr.w PlaySound ; play boss musicReplace them ALL with:

Code:

		move.b	($FFFFFE10).w,d0	; set boss number
		lea	(MusicList8).l,a1	; load Music Playlist for bosses
		move.b	(a1,d0.w),d0	; get d0-th entry from the playlist
		bsr.w	PlaySound	; play boss music
		move.b	#1,($FFFFFFFF).w	; set boss flag

Keep whatever there is above and below (typically stuff which involves $FFFFF742 and $FFFFF7AA).

Now, this is even more boring. Find these 5 things:

Code:

loc_179E0:
		clr.w	$12(a0)
		move.w	#$81,d0
		jsr	(PlaySound).l	; play GHZ music

Code:

loc_18112:
		move.w	#$82,d0
		jsr	(PlaySound).l	; play LZ music
		bset	#0,$22(a0)
		addq.b	#2,$25(a0)

Code:

loc_1856C:
		clr.w	$12(a0)
		move.w	#$83,d0
		jsr	(PlaySound).l	; play MZ music

Code:

loc_18BB4:
		clr.w	$12(a0)
		move.w	#$84,d0
		jsr	(PlaySound).l	; play SLZ music

Code:

loc_194E0:
		clr.w	$12(a0)
		move.w	#$85,d0
		jsr	(PlaySound).l	; play SYZ music

Replace them, respectively, with:

Code:

loc_179E0:
		clr.w	$12(a0)
		
		clr.w	d0
		move.b	d0,$FFFFFFFF	; clear Boss flag
		cmpi.b	#$1,($FFFFFE2D).w	; does Sonic have invincibility?
		beq.b	loc_179E0_inv 	; if yes, load invincibility music
		cmpi.b	#$1,($FFFFFE2E).w	; does Sonic have speed shoes?
		beq.b	loc_179E0_speed	; if yes, load speed shoes music

		move.b	$FFFFFFFE,d0	; loads music from RAM
		bra.s	loc_179E0_play

loc_179E0_speed:
		move.b	#$FB,d0
		bra.s	loc_179E0_play
loc_179E0_inv:
		cmpi.b	#$1,($FFFFFE2E).w	; does Sonic have also speed shoes?
		beq.s	loc_179E0_inv_and_speed
		move.b	#$87,d0
		bra.s	loc_179E0_play
loc_179E0_inv_and_speed:
		move.b	#$F2,d0
loc_179E0_play:
		jsr	(PlaySound).l	; play some music

Code:

loc_18112:
		clr.w	d0
		move.b	d0,$FFFFFFFF	; clear Boss flag

		cmpi.b	#$1,($FFFFFE2D).w	; does Sonic have invincibility?
		beq.b	loc_18112_inv 	; if yes, load invincibility music
		cmpi.b	#$1,($FFFFFE2E).w	; does Sonic have speed shoes?
		beq.b	loc_18112_speed	; if yes, load speed shoes music
		move.b	$FFFFFFFE,d0	; loads music from RAM
		bra.s	loc_18112_play
loc_18112_speed:
		move.b	#$FB,d0
		bra.s	loc_18112_play
loc_18112_inv:
		cmpi.b	#$1,($FFFFFE2E).w	; does Sonic have also speed shoes?
		beq.s	loc_18112_inv_and_speed
		move.b	#$87,d0
		bra.s	loc_18112_play
loc_18112_inv_and_speed:
		move.b	#$F2,d0
loc_18112_play:
		jsr	(PlaySound).l	; play some music
		bset	#0,$22(a0)
		addq.b	#2,$25(a0)

Code:

loc_1856C:
		clr.w	$12(a0)
		clr.w	d0
		move.b	d0,$FFFFFFFF	; clear Boss flag
		cmpi.b	#$1,($FFFFFE2D).w	; does Sonic have invincibility?
		beq.b	loc_1856C_inv 	; if yes, load invincibility music
		cmpi.b	#$1,($FFFFFE2E).w	; does Sonic have speed shoes?
		beq.b	loc_1856C_speed	; if yes, load speed shoes music
		move.b	$FFFFFFFE,d0	; loads music from RAM
		bra.s	loc_1856C_play
loc_1856C_speed:
		move.b	#$FB,d0
		bra.s	loc_1856C_play
loc_1856C_inv:
		cmpi.b	#$1,($FFFFFE2E).w	; does Sonic have also speed shoes?
		beq.s	loc_1856C_inv_and_speed
		move.b	#$87,d0
		bra.s	loc_1856C_play
loc_1856C_inv_and_speed:
		move.b	#$F2,d0
loc_1856C_play:
		jsr	(PlaySound).l	; play some music

Code:

loc_18BB4:
		clr.w	$12(a0)
		clr.w	d0
		move.b	d0,$FFFFFFFF	; clear Boss flag
		cmpi.b	#$1,($FFFFFE2D).w	; does Sonic have invincibility?
		beq.b	loc_18BB4_inv 	; if yes, load invincibility music
		cmpi.b	#$1,($FFFFFE2E).w	; does Sonic have speed shoes?
		beq.b	loc_18BB4_speed	; if yes, load speed shoes music
		move.b	$FFFFFFFE,d0	; loads music from RAM
		bra.s	loc_18BB4_play
loc_18BB4_speed:
		move.b	#$FB,d0
		bra.s	loc_18BB4_play
loc_18BB4_inv:
		cmpi.b	#$1,($FFFFFE2E).w	; does Sonic have also speed shoes?
		beq.s	loc_18BB4_inv_and_speed
		move.b	#$87,d0
		bra.s	loc_18BB4_play
loc_18BB4_inv_and_speed:
		move.b	#$F2,d0
loc_18BB4_play:
		jsr	(PlaySound).l	; play some music

Code:

loc_194E0:
		clr.w	$12(a0)
		clr.w	d0
		move.b	d0,$FFFFFFFF	; clear Boss flag
		cmpi.b	#$1,($FFFFFE2D).w	; does Sonic have invincibility?
		beq.b	loc_194E0_inv 	; if yes, load invincibility music
		cmpi.b	#$1,($FFFFFE2E).w	; does Sonic have speed shoes?
		beq.b	loc_194E0_speed	; if yes, load speed shoes music
		move.b	$FFFFFFFE,d0	; loads music from RAM
		bra.s	loc_194E0_play
loc_194E0_speed:
		move.b	#$FB,d0
		bra.s	loc_194E0_play
loc_194E0_inv:
		cmpi.b	#$1,($FFFFFE2E).w	; does Sonic have also speed shoes?
		beq.s	loc_194E0_inv_and_speed
		move.b	#$87,d0
		bra.s	loc_194E0_play
loc_194E0_inv_and_speed:
		move.b	#$F2,d0
loc_194E0_play:
		jsr	(PlaySound).l	; play some music

All this code ensures that the correct song is played after a boss is defeated; also, Invincibility and/or Speed Shoes songs are restored instead. I understand that this step is long and boring, but it's unavoidable. Of course, the meaning of $F2, $FB, and $87, is still the same from the previous steps. The Speed Shoes check in LZ can be probably removed, but it's there for consistency.

 

Step 5: «oh fuck oh fuck air bubble air bubble»


I wanted to take care of the boss music in the previous step, to introduce the concept of Playlist 8. Now the replacement below will make much more sense.


Find:

ResumeMusic: ; XREF: Obj64_Wobble; Sonic_Water; Obj0A_ReduceAir
cmpi.w #$C,($FFFFFE14).w
bhi.s loc_140AC
move.w #$82,d0 ; play LZ music
cmpi.w #$103,($FFFFFE10).w ; check if level is 0103 (SBZ3)
bne.s loc_140A6
move.w #$86,d0 ; play SBZ music

loc_140A6:
jsr (PlaySound).lReplace it with:

Code:

ResumeMusic:				; XREF: Obj64_Wobble; Sonic_Water; Obj0A_ReduceAir
		cmpi.w	#$C,($FFFFFE14).w
		bhi.b	loc_140AC

		cmpi.b	#$1,($FFFFFFFF).w	; am I fighting the boss?
		bne.s	NotBoss	; if not, branch
		move.b	($FFFFFE10).w,d0	; set boss number
		lea	(MusicList8).l,a1	; load Music Playlist for bosses
		move.b	(a1,d0.w),d0	; get d0-th entry from the playlist
		bra.s	loc_140A6

NotBoss:
		cmpi.b	#$1,($FFFFFE2D).w	; am I invincible?
		bne.s	NotInv	; if not, branch
		move.b	#$87,d0
		bra.s	loc_140A6

NotInv:
		move.b	$FFFFFFFE,d0	; loads song number from RAM
loc_140A6:
		jsr	(PlaySound).l

Look at the magic of $FFFFFFFE. Once again, no need to recheck zone and act: the correct song ID will always be there. Playlist 8 is used to play the boss song if you breathe while fighting the LZ boss, and invincibility is checked, to play the appropriate song instead of the level theme (but it's checked after the Boss is checked (via $FFFFFFFF), since I give priority to the Boss music). Again, replace $87 with another ID if you used another song for invincibility in your hack. Speed Shoes aren't checked because they shouldn't exist in Labyrinth Zone. Feel free to improve this code if you applied the guide which properly handle Speed Shoes in water levels -- it's only a matter of adding a couple of checks.

This step was simple, wasn't it?

 

Step 6: Special Stages


Find these two lines:

Code:

		move.w	#$89,d0
		bsr.w	PlaySound	; play special stage BG	music

Things are about to get MUCH beefier. Replace them with:

Code:

		moveq	#0,d0
		move.b	($FFFFFE16).w,d0
		cmpi.b	#$0,d0
		bne.b SS_Num_Not_Zero
		move.b	#$6,d0

SS_Num_Not_Zero:
		subi.w	#$1,d0

		lea	(MusicList5).l,a1 ; load Music Playlist for Special Stages
		move.b	(a1,d0.w),d0 ; get d0-th entry from the playlist
		bsr.w	PlaySound	; play special stage BG	music

This code takes the Special Stage number -1, don't ask me why, but it works in this way.

 

Step 7: ending and credits


If you want, you can have different songs to play in the mini-GHZ at the end, as well as during the Staff Roll, depending if you collected the 6 chaos emeralds or not.


Find:


move.w #$600,($FFFFFE10).w ; set level number to 0600 (extra flowers)Below that line, add:

Code:

		move.b	#$0,($FFFFFFFD).w	; puts a 0 in this flag

Find:

Code:

		move.w	#$601,($FFFFFE10).w ; set level	number to 0601 (no flowers)

Below that line, add:

Code:

		move.b	#$1,($FFFFFFFD).w	; puts a 1 in this flag

In this way, a new flag is created, at (usually unused) RAM address $FFFFFFFD. 0 means good ending, 1 means bad ending.

Find:

Code:

		move.w	#$8B,d0
		bsr.w	PlaySound	; play ending sequence music

Replace it with:

Code:

		move.b	($FFFFFFFD).w,d0
		lea	(MusicList7).l,a1 ; load Music Playlist for Endings
		move.b	(a1,d0.w),d0 ; get d0-th entry from the playlist

Find:

Code:

		move.b	#$91,d0
		bsr.w	PlaySound_Special ; play credits music
		move.w	#0,($FFFFFFF4).w ; set credits index number to 0
		rts

Replace it with:

Code:

		clr.w	d0
		move.b	($FFFFFFFD).w,d0	; get kind of ending (0 = good, 1 = bad)
		lea	(MusicList6).l,a1	; load Music Playlist for credits
		move.b	(a1,d0.w),d0	; get d0-th entry from the playlist

		bsr.w	PlaySound_Special ; play credits music
		move.w	#0,($FFFFFFF4).w ; set credits index number to 0
		rts

This was another simple step.

 

Step 8: set up the new playlists


Delete files miscmuslist1.bin and miscmuslist2.bin; I thought it would make more sense to have the playlists in the "sound" directory instead of "misc".


So, go to the "sound" directory and create files with the following HEX contents (to mimic a clean Sonic 1 setup).

• soundmuslist1.bin:
  Code:

  81 82 83 84 85 86

• soundmuslist2.bin:
  Code:

  81 82 83 84 85 86

• soundmuslist3.bin:
  Code:

  81 82 83 84 85 8D

  (note that the last byte refers to SBZ3 aka FZ)
• soundmuslist4.bin:
  Code:

  xx 86 xx xx xx xx

  (xx means any value, since the only Act 4 slot is used for LZ4 aka SBZ3)
• soundmuslist5.bin:
  Code:

  89 89 89 89 89 89

• soundmuslist6.bin:
  Code:

  91 91

• soundmuslist7.bin:
  Code:

  8B 8B

• soundmuslist8.bin:
  Code:

  8C 8C 8C 8C 8C

You can now alter those values to suit your needs. Good luck finding that many songs.

 

Aha, nice work there.

You've nicely aligned code boxes between text, used clean font sizes, and split the parts up into individual posts. I'm in favour of such a wonderfully clean and well presented guide! God knows how difficult that must have been given how fussy I.P.B can be =I

 

I'm glad you've also fixed that issue where in stock Sonic 1 uses an alternate music list for returning the music to normal after you get invincibility.

 

Thanks

 

I saw a small problem, but isn't a problem rightly.

The Special Stage playlist, is untidy; so, for example, this is an example of music order for SS: 01 02 03 04 05 06

When I put these numbers in the playlist, the game don't recognizes the real order, and the game plays in this order: 06 01 02 03 04 05

Only to fix this, this will be the order: 02 03 04 05 06 01

Anyways, all works wonderful! Good job nineko!

Edit: Grammar

 

This is weird, I remember the Special Stage number was being off by one for some reason when I worked on my hack, so I had to insert a "-1" there (the "subi.w #$1,d0", but only if the number isn't 0). I tried to apply that code to a clean disassembly, and it worked fine. Try to remove everything from the cmpi.b to the subi.w, it is possible that you did something else which fixes the "-1" anomaly.

 

Meh, isn't a big problem, and I tested it a lot of times when it has been repaired. All works fine.

 

The Special Stage issue; it depends exactly where this code is placed as to whether or not the -1 issue is relevant. The reason for it is there's a piece of code before it that uses that Special Stage number to determine which Layout to use, then increments it to the next one you haven't beaten. It does this at the beginning of the Special Stage rather than at the end, as by that point it doesn't matter what is there; the Emerald you get isn't chosen by the Special Stage number, but by SS object number.

Placing the check before this happens and storing it in your RAM variable for later use of playing would solve the issue. I'll try to find the relevant code later, as I don't have time right now. :U

 

Yeah, I guessed it had something to do with the Special Stage number being already incremented for the next one, but I couldn't figure out where to perform the check otherwise. This also means that my code above has been wrong for all this time, because if you didn't collect an emerald and you go back to a previous stage later, the -1'd Special Stage number might be one you already completed, so a better place for this code is necessary. I never thought about this because I never fail to collect the emeralds :|