Mini-tutorials Thread

This is a nice guide, but there is a small, probably insignificant oversight; since the time resets, then getting the time bonus becomes very easy, depending on the situation. Depending on the hack, it might make sense to set the timer to a particular time, (like 5 minutes or something) to avoid inadvertently rewarding the time over. Again, it's probably insignificant, but I felt it was worth mentioning.

 

It's true, the oversight does exist in the original games as well. I have taken advantage of it myself in Sonic 2, using the last checkpoint of one of the Metropolis acts to gain 50000 points and trivialize the effect of the time over. One could set up a flag that nullifies the time bonus when set. Might write up something later once I get home...

 

To make the sonic 2 drums sound like the sonic 1 prototype drums, go into s2.sounddriver.asm and go to
zDACMasterPlaylist
you will see these lines

Code:

    db    id(zDACPtr_Sample1),17h        ; 81h
    db    id(zDACPtr_Sample2),1        ; 82h
    db    id(zDACPtr_Sample3),6        ; 83h
    db    id(zDACPtr_Sample4),8        ; 84h
    db    id(zDACPtr_Sample5),1Bh        ; 85h
    db    id(zDACPtr_Sample6),0Ah        ; 86h
    db    id(zDACPtr_Sample7),1Bh        ; 87h
    db    id(zDACPtr_Sample5),12h        ; 88h
    db    id(zDACPtr_Sample5),15h        ; 89h
    db    id(zDACPtr_Sample5),1Ch        ; 8Ah
    db    id(zDACPtr_Sample5),1Dh        ; 8Bh
    db    id(zDACPtr_Sample6),2        ; 8Ch
    db    id(zDACPtr_Sample6),5        ; 8Dh
    db    id(zDACPtr_Sample6),8        ; 8Eh
    db    id(zDACPtr_Sample7),8        ; 8Fh
    db    id(zDACPtr_Sample7),0Bh        ; 90h
    db    id(zDACPtr_Sample7),12h        ; 91h

to lower their pitch, you add numbers to them, to make them sound like the sonic 1 prototype drums, replace it with this

Code:

    db    id(zDACPtr_Sample1),19h        ; 81h
    db    id(zDACPtr_Sample2),6        ; 82h
    db    id(zDACPtr_Sample3),6    ; 83h
    db    id(zDACPtr_Sample4),8        ; 84h
    db    id(zDACPtr_Sample5),20h        ; 85h
    db    id(zDACPtr_Sample6),0Fh        ; 86h
    db    id(zDACPtr_Sample7),20h        ; 87h
    db    id(zDACPtr_Sample5),17h        ; 88h
    db    id(zDACPtr_Sample5),1Ah        ; 89h
    db    id(zDACPtr_Sample5),22h        ; 8Ah
    db    id(zDACPtr_Sample5),23h        ; 8Bh
    db    id(zDACPtr_Sample6),0Ch        ; 8Ch
    db    id(zDACPtr_Sample6),0Ah        ; 8Dh
    db    id(zDACPtr_Sample6),0Dh        ; 8Eh
    db    id(zDACPtr_Sample7),0Dh        ; 8Fh
    db    id(zDACPtr_Sample7),0Bh        ; 90h
    db    id(zDACPtr_Sample7),12h        ; 91h

then build your rom
Sample 1 is the Kick
Sample 2 is the Snare
Sample 3 is the Clap
Sample 4 is the Record Scratch from MTZ
Sample 5 is the Timpani
Sample 6 is the Toms
Sample 7 is the Bongo from MCZ

 

Green hill death bug (Github)

if you have gone at high speed on the first level of green hill it will have happened to you that you died because of too much speed


To fix this it's easy, open DynamicLevelEvents inside the _inc folder, go to "DLE_GHZ1:" without the quotes and copy this code

Code:

DLE_GHZ1:

        move.w    #$300,(v_limitbtm1).w ; set lower y-boundary
        move.w    #$300,(v_limitbtm2).w ; set lower y-boundary; <----- insert this.
        cmpi.w    #$1780,(v_screenposx).w ; has the camera reached $1780 on x-axis?
        bcs.s    locret_6E08    ; if not, branch
        move.w    #$400,(v_limitbtm1).w ; set lower y-boundary
        move.w    #$400,(v_limitbtm2).w ; set lower y-boundary; <----- insert this.
locret_6E08:
        rts    

and ready the camera will go faster

 

Your videos are set to private. They should be unlisted. Funnily enough, this is almost 1:1 how Sonic Jam fixes it, except it doesn't put in this:

 

thanks for the warning

 

How to stop or change the scrolling speed of the background on the title screen in Sonic 1

Good day! Today I will show you another guide. Many rom hackers, more advanced than me, know how to do this, but still, it will be useful for someone who is just starting his hacking activity. We want beginners to do good hacks So, let's begin. I will give a guide for as many as three disassembles: Hivebrain 2005, GitHub and SVN.

Hivebrain 2005:

Looking for loc_317C: and see:

Code:

loc_317C:
        move.b    #4,($FFFFF62A).w
        bsr.w    DelayProgram
        jsr    ObjectsLoad
        bsr.w    DeformBgLayer
        jsr    BuildSprites
        bsr.w    PalCycle_Title
        bsr.w    RunPLC_RAM
        move.w    ($FFFFD008).w,d0
        addq.w    #2,d0
        move.w    d0,($FFFFD008).w ; move    Sonic to the right
        cmpi.w    #$1C00,d0    ; has Sonic object passed x-position $1C00?
        bcs.s    Title_ChkRegion    ; if not, branch
        move.b    #0,($FFFFF600).w ; go to Sega screen
        rts

So, we need this line here:

Code:

addq.w    #2,d0

Here you can change the speed from 1 to 8. Unfortunately, it is impossible to do more. (forget my words, this can be done simply by replacing addq.w #2,d0 with addi.w #2,d0. Thanks to Inferno Gear for the advice.) So, just change to these numbers and that's it. The scrolling speed will change. If you want to stop scrolling completely, then do not change the value to 0 in any case, otherwise the compiler will give this error: (forget it all, guys lol)

Code:

S1 HIVEBRAIN 2005 DISASM\SONIC1.ASM(3266) : Error : Illegal value (0)
 addq.w #0,d0

So, comment out or delete this line here addq.w #2,d0. But I advise you to comment.

GitHub/SVN:

Many rom hackers know that GitHub disassembly was built on SVN disassembly, so both there and there, the code is the same.

And so, look for Tit_MainLoop:
(both in SVN and in GitHub everything is completely the same)

and we see it:

Code:

Tit_MainLoop:
        move.b    #4,(v_vbla_routine).w
        bsr.w    WaitForVBla
        jsr    (ExecuteObjects).l
        bsr.w    DeformLayers
        jsr    (BuildSprites).l
        bsr.w    PCycle_Title
        bsr.w    RunPLC
        move.w    (v_objspace+obX).w,d0
        addq.w    #2,d0
        move.w    d0,(v_objspace+obX).w ; move Sonic to the right
        cmpi.w    #$1C00,d0    ; has Sonic object passed $1C00 on x-axis?
        blo.s    Tit_ChkRegion    ; if not, branch

        move.b    #id_Sega,(v_gamemode).w ; go to Sega screen
        rts

And we will need exactly the same line addq.w #2,d0 and you know what to do with it. Done. Compile and check, everything works ;>

EDIT: idk

 

... actually, this is completely false, as all that the line does is change the X position of the object in Sonic's slot, determining the current camera position.

In order to do more, change it from addq to addi. This will be slightly slower but allow you to add more than 8 at a time.

 

@Inferno oh! I didn't even know about it. Thank you, I'll know now, cap

 

EDIT: Nevermind.

 

How to make camera moving with you when you dead like in Sonic 2 beta 4 and 5 (Sonic 2 GitHub disasm):

Find it:

Code:

CheckGameOver:

And comment this line:

Code:

move.b    #1,(Scroll_lock).w

Done

How to restore burned death animation (Sonic 2 GitHub disasm):
Find

Code:

KillCharacter:

And before this:

Code:

move.b    #AniIDSonAni_Death,anim(a0)

Insert this:

Code:

cmpi.b  #$31,(a2); Test for object ID (Lava in MTZ and HTZ)
    beq.s    Pizdec; Is it? Go to this label
    cmpi.b  #$95,(a2); Test for object ID (Soul in HTZ)
    beq.s    Pizdec; Go to this label

This code checks object that hurts you, and make you go to this (should be placed before Touch_Special):

Code:

Pizdec:
    move.b    #AniIDSonAni_DeathBW,anim(a0)
    bset    #high_priority_bit,art_tile(a0)
    move.w    #SndID_Hurt,d0
    jsr    (PlaySound).l
+
    moveq    #-1,d0
    rts

It's should work:




It's all! If you had any questions- ask me

 

Very Mini Tutorial: How to unlock sonic and tails directional control after a roll jump
in Sonic_RollJump and Tails_RollJump, there is this line

Code:

bset    #4,status(a0)    ; set the rolling+jumping flag

remove it for each character
when you build, sonic and tails will be able to change directions after a roll jump.
For best results, also remove the air speed cap https://info.sonicretro.org/SCHG_How-to:Remove_the_Air_Speed_Cap

 

It should be noted that if you don't remove the air speed cap, then if you hold left or right while in the air, and you're going really fast, then the speed cap will kick in and ruin your momentum. The roll jump flag basically helps maintain the momentum by locking your controls, and thus disallowing the speed cap from ever kicking in.

For example, in Sonic 1. With roll jump lock + air speed cap:


No roll jump lock + air speed cap kept in:


So, yeah, remove the air speed cap, too.

 

That is really interesting. This also happened in Sonic 2, as I have played that a couple of times now, and did notice this air-speed cap issue when I did the same thing you mentioned when roll-jumping causes you to get locked at that air speed cap, especially when jumping after spindashing or jumping while gaining momentum on a slope.

It seems that while the ground speed cap is removed in Sonic 2, the air speed cap was retained. There is a guide on Retro that explains how to remove the air speed cap. Sonic 3, Sonic & Knuckles, and Sonic 3 & Knuckles removed the air speed cap from Sonic 2 for the same purpose.

 

Have you ever felt that doing the Level Order in Sonic 1 2005 disasm is hard by doing hex editing? Then look no further than this easy way to do a Level Order.
If you hate doing hex editing that thing, then this is for you!
So go to "LevelOrder", and remove the old level order which is a binary file with the "even" as well. Don't remove the label "LevelOrder". Otherwise you'd get build errors.
It would look something like this:

Code:

LevelOrder:
   incbin misc/lvl_ord.bin
    even

Now paste this code which simplifies it from Hex to Assembly.

Code:

 ; Green Hill Zone
        dc.b 0, 1    ; Act 1
        dc.b 0, 2    ; Act 2
        dc.b 2, 0    ; Act 3
        dc.b 0, 0

        ; Labyrinth Zone
        dc.b 1, 1    ; Act 1
        dc.b 1, 2    ; Act 2
        dc.b 3, 0    ; Act 3
        dc.b 5, 2    ; Scrap Brain Zone Act 3

        ; Marble Zone
        dc.b 2, 1    ; Act 1
        dc.b 2, 2    ; Act 2
        dc.b 4, 0    ; Act 3
        dc.b 0, 0

        ; Star Light Zone
        dc.b 3, 1    ; Act 1
        dc.b 3, 2    ; Act 2
        dc.b 5, 0    ; Act 3
        dc.b 0, 0

        ; Spring Yard Zone
        dc.b 4, 1    ; Act 1
        dc.b 4, 2    ; Act 2
        dc.b 1, 0    ; Act 3
        dc.b 0, 0

        ; Scrap Brain Zone
        dc.b 5, 1    ; Act 1
        dc.b 1, 3    ; Act 2
        dc.b 0, 0    ; Final Zone
        dc.b 0, 0
        even

Now if you don't know what's happening here. Essentially, the first number represents the zone and second number represents the act.
And where the act is zero, means that stage will play after the act.

Like let's say I want spring yard to play after GHZ. I'll make dc.b 2, 0 to dc.b 4,0. So now after I beat act 3 of GHZ. SYZ would play. How cool is that?!?!?

Also the zones are in 0 to 5.
Like how shown here. 0 is GHZ, 1 is LZ, 2 is MZ, 3 is SLZ, 4 is SYZ and 5 is SBZ.
No credits should be given. It's a simple thing you could do.

Oh and btw to those who are using the GitHub disassembly, you already have that in Object 3A. And those who are using the ReadySonic disasm. You can use this tutorial.
Have fun!
Edit: fixed some stuff, see the message below.

 

The guide itself is, essentially, an unequated version of this guide. It also forgets to mention one key pointer.

The guide fails to mention that the LevelOrder label should be preserved. The second block of code, which lacks the LevelOrder label, may accidentally suggest that it should be removed, which is incorrect, as by doing so, it will cause the assembler to stop recognizing the level order, resulting in building errors.

It's a pretty simple fix, though. All that really needs to be done is adding the "LevelOrder:" label back, right above the second block of code. Now, I don't like being that guy, but I still feel it should have been mentioned.

 

Ah, I forgot to mention about that. But yeah, I should've mentioned that. Thanks for the warning.
And I never saw that tutorial as well so uhh.

 

How to implement music/sound in Level Select, as in Sonic 2 in Sonic 1 (Hivebrain 2005, GitHub/SVN)

Good day!

Today I will tell you how to insert music into Level Select to make it look better. It's very easy. Let's get started. As usual, I'm doing a mini-guide on several Sonic 1 showdowns - Hivebrain 2005, GitHub and SVN.

Hivebrain 2005:

So, we are looking for:

Code:

LevelSelect:

Well, and before this subroutine we put this code:

Code:

LSMusicLoader:
        move.b    #$XX,d0 ; replace with a slot with music (any one you want)
        bsr.w    PlaySound_Special ; EddyTF: this "Level Select OST" branch lol

That's all. Compile and test. The function is successfully enabled and works)

GitHub/SVN:

Looking for:

Code:

LevelSelect:

This is the same as in Hive 2005 Disasm, oddly enough)

And before that we insert something like this:

Code:

LSMusicLoader:
        move.b    #bgm_XX,d0 ; insert the name of any music (that you want to play)
        bsr.w    PlaySound_Special ; EddyTF: fuck i'm writing this again idk

And everything. Everything should work fine.

I hope my mini-guide was useful.

 

There's an easy way to do that, as shown in this tutorial: https://info.sonicretro.org/SCHG_Ho...evel_Select_in_Sonic_1#Level_Select_Music_Fix
Simply, go to "Title_ClrVram" and under the dbf line. Add the music thing.

But this can also work. So yeah. I wanted to point that out.

 

@Dark Shamil Khan Oh! To be honest, I didn't even know about this lol, but nevertheless this is my personal method. It also works, but is located in a completely different place. Thanks for the advice)