Difference between revisions of "Add final spindash to Sonic 2 Beta"
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− | + | {{GuideBy|Shadow05}} | |
− | + | ||
− | Well this guide is for people who can do basic | + | If you’ve ever played [[Sonic 2 Beta]] before, chances are you may have been annoyed about the incomplete Spindash. Well, this guide will show you how to port the Spindash from the final build of Sonic 2. This guide is made is for people who can do some basic ASM editing, and was inspired by the Sonic 1 Spindash guide. |
− | I | + | |
+ | I will be using [[User:Super Egg|Super Egg]]'s disassembly for this guide, but this should work on [[User:Esrael|Esrael]]'s original disassembly. This guide would also work with the [[Sonic 2 Nick Arcade]] prototype as well, as it uses the exact same spindash system. | ||
===Directly copying the object code=== | ===Directly copying the object code=== | ||
− | First we'll have to get a slightly modified | + | First, we'll have to get a slightly modified version of the Sonic 1 Spindash code. |
− | Replace the entire routine with this | + | Search for "Sonic_SpinDash:". Replace the entire routine with this: |
<syntaxhighlight lang="asm"> | <syntaxhighlight lang="asm"> | ||
Line 110: | Line 111: | ||
</syntaxhighlight> | </syntaxhighlight> | ||
− | ===Fixing | + | ===Fixing errors=== |
− | + | The coding is now there; however, when you get to building the ROM you will most likely encounter an error. | |
− | when you | + | To fix this issue, go to line 25863. You’ll see this line below: |
− | |||
<syntaxhighlight lang="asm"> | <syntaxhighlight lang="asm"> | ||
bra loc_FBF4 | bra loc_FBF4 | ||
</syntaxhighlight> | </syntaxhighlight> | ||
− | + | Delete it (or comment it out; it doesn’t matter). | |
− | + | Note that if you are doing this on the Nick Arcade disassembly (text or split), this error won't happen. | |
− | + | ===Conclusion=== | |
+ | And that’s it. If I was doing a part 2 of this guide, a lot of steps for the Nick Arcade and Simon Wai disassemblies would be the same as in the Sonic 1 tutorial for adding the Spindash, such as fixing the Monitor Bug, adding the sound effects, etc. Refer to those once you’ve got the Spindash working. | ||
+ | Thanks for reading this guide; hopefully you'll be less annoyed about the incomplete Spindash. | ||
+ | |||
+ | {{S2NAHowtos}} | ||
{{S2BHowtos}} | {{S2BHowtos}} | ||
− | |||
− |
Latest revision as of 16:33, 28 July 2023
(Original guide by Shadow05)
If you’ve ever played Sonic 2 Beta before, chances are you may have been annoyed about the incomplete Spindash. Well, this guide will show you how to port the Spindash from the final build of Sonic 2. This guide is made is for people who can do some basic ASM editing, and was inspired by the Sonic 1 Spindash guide.
I will be using Super Egg's disassembly for this guide, but this should work on Esrael's original disassembly. This guide would also work with the Sonic 2 Nick Arcade prototype as well, as it uses the exact same spindash system.
Directly copying the object code
First, we'll have to get a slightly modified version of the Sonic 1 Spindash code.
Search for "Sonic_SpinDash:". Replace the entire routine with this:
Sonic_SpinDash:
tst.b $39(a0)
bne.s loc_1AC8E
cmpi.b #8,$1C(a0)
bne.s locret_1AC8C
move.b ($FFFFF603).w,d0
andi.b #$70,d0
beq.w locret_1AC8C
move.b #9,$1C(a0)
move.w #$E0,d0
jsr (Play_Sfx)
addq.l #4,sp
move.b #1,$39(a0)
move.w #0,$3A(a0)
cmpi.b #$C,$28(a0)
bcs.s loc_1AC84
move.b #2,($FFFFD11C).w
loc_1AC84:
locret_1AC8C:
rts
; ---------------------------------------------------------------------------
loc_1AC8E:
move.b ($FFFFF602).w,d0
btst #1,d0
bne.w loc_1AD30
move.b #$E,$16(a0)
move.b #7,$17(a0)
move.b #2,$1C(a0)
addq.w #5,$C(a0)
move.b #0,$39(a0)
moveq #0,d0
move.b $3A(a0),d0
add.w d0,d0
move.w Dash_Speeds(pc,d0.w),$14(a0)
move.w $14(a0),d0
subi.w #$800,d0
add.w d0,d0
andi.w #$1F00,d0
neg.w d0
addi.w #$2000,d0
move.w d0,($FFFFEED0).w
btst #0,$22(a0)
beq.s loc_1ACF4
neg.w $14(a0)
loc_1ACF4:
bset #2,$22(a0)
move.b #0,($FFFFD11C).w
move.w #$BC,d0
jsr (Play_Sfx)
bra.s loc_1AD78
; ===========================================================================
Dash_Speeds: dc.w $800 ; 0
dc.w $880 ; 1
dc.w $900 ; 2
dc.w $980 ; 3
dc.w $A00 ; 4
dc.w $A80 ; 5
dc.w $B00 ; 6
dc.w $B80 ; 7
dc.w $C00 ; 8
; ===========================================================================
loc_1AD30: ; If still charging the dash...
tst.w $3A(a0)
beq.s loc_1AD48
move.w $3A(a0),d0
lsr.w #5,d0
sub.w d0,$3A(a0)
bcc.s loc_1AD48
move.w #0,$3A(a0)
loc_1AD48:
move.b ($FFFFF603).w,d0
andi.b #$70,d0 ; 'p'
beq.w loc_1AD78
move.w #$900,$1C(a0)
move.w #$E0,d0 ; changed from #$E0
jsr (Play_Sfx)
addi.w #$200,$3A(a0)
cmpi.w #$800,$3A(a0)
bcs.s loc_1AD78
move.w #$800,$3A(a0)
loc_1AD78:
addq.l #4,sp
cmpi.w #$60,($FFFFEED8).w
beq.s loc_1AD8C
bcc.s loc_1AD88
addq.w #4,($FFFFEED8).w
loc_1AD88:
subq.w #2,($FFFFEED8).w
loc_1AD8C:
rts
; End of subroutine Sonic_SpinDash
Fixing errors
The coding is now there; however, when you get to building the ROM you will most likely encounter an error. To fix this issue, go to line 25863. You’ll see this line below:
bra loc_FBF4
Delete it (or comment it out; it doesn’t matter).
Note that if you are doing this on the Nick Arcade disassembly (text or split), this error won't happen.
Conclusion
And that’s it. If I was doing a part 2 of this guide, a lot of steps for the Nick Arcade and Simon Wai disassemblies would be the same as in the Sonic 1 tutorial for adding the Spindash, such as fixing the Monitor Bug, adding the sound effects, etc. Refer to those once you’ve got the Spindash working.
Thanks for reading this guide; hopefully you'll be less annoyed about the incomplete Spindash.
SCHG How-To Guide: Sonic 2 Nick Arcade (16-bit) |
---|
Fixing Bugs |
Fix EHZ Deformation Bug |
Design Choices |
Add final spindash to Sonic 2 Beta | How to port paralax plouds to the Nick Arcade prototype |
SCHG How-To Guide: Sonic 2 Beta (16-bit) |
---|
Fixing Bugs |
Fix EHZ Deformation Bug |
Design Choices |
Add final spindash to Sonic 2 Beta |