Difference between revisions of "Sonic 2 (Simon Wai Prototype) Level Select in Sonic 1"
From Sonic Retro
m (Minor edits) |
m (Some cleanup) |
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− | You probably wonder why Sonic 2 | + | {{GuideBy|Kram1024}} |
+ | |||
+ | You probably wonder why Sonic 2 Beta has that level select that looks almost like the Sonic 1 level select, and how Sonic 2 Nick Arcade prototype has one that '''is''' the Sonic 1 level select. Well, '''that''' is what we are going to make the one in Sonic 1 behave like. | ||
===Overview=== | ===Overview=== | ||
− | First, | + | First, let's look at an overview of what our level select code looks like normally in Sonic 1 (this is from the Hivebrain disassembly): |
<asm> | <asm> | ||
; --------------------------------------------------------------------------- | ; --------------------------------------------------------------------------- | ||
Line 113: | Line 115: | ||
===Button Fix, Part 1=== | ===Button Fix, Part 1=== | ||
− | A lot of stuff we really do not need, as well as the | + | A lot of stuff here we really do not need, as well as the fact that all buttons that are not the D-Pad seem to be used to play a sound or select a level. Let's fix that. |
<asm> | <asm> | ||
LevelSelect: | LevelSelect: | ||
Line 147: | Line 149: | ||
</asm> | </asm> | ||
− | + | We do not need the Japanese credits code, removed that junk. As for the levels, we want to start them with the start button but not exclusively just the start button, so an andi would be used there. Also, we want start to exit back to the Sega screen, and why not some nice music? Only B or C should play something on the sound test. | |
− | + | The results should look like this: | |
<asm> | <asm> | ||
Line 194: | Line 196: | ||
===Level Select Music Fix=== | ===Level Select Music Fix=== | ||
− | That fixes the level select so that it runs levels in a | + | That fixes the level select so that it runs levels in a Sonic 2 manner, but it doesn't fix the music. Let's do that now. |
− | + | Find: | |
<asm> | <asm> | ||
Title_ClrVram: | Title_ClrVram: | ||
Line 221: | Line 223: | ||
bsr.w LevSelTextLoad | bsr.w LevSelTextLoad | ||
</asm> | </asm> | ||
− | Green Hill Zone music at the level select, how lovely. | + | Green Hill Zone music at the level select, how lovely. On the other hand, if you plan on using [[SCHG_How-to:Port_Sonic_2_Final_Sound_Driver_to_Sonic_1 | my Sonic 2 Sound Driver port]], try using music number $91 and PlayMusic as opposed to PlaySound. |
===Button Fix, Part 2=== | ===Button Fix, Part 2=== | ||
As you already know, the A button is not yet fixed, time to fix that button: | As you already know, the A button is not yet fixed, time to fix that button: | ||
− | First We will have to edit the "LevSel_SndTest" routine. | + | First We will have to edit the "LevSel_SndTest" routine. $C (left and right) will not work for detecting an A button. We will need $4C (A/Left/Right) instead, so look in our function for: |
<asm> | <asm> | ||
LevSel_SndTest: ; XREF: LevSelControls | LevSel_SndTest: ; XREF: LevSelControls | ||
Line 260: | Line 262: | ||
</asm> | </asm> | ||
− | + | Now locate: | |
<asm> | <asm> | ||
bcc.s LevSel_Right | bcc.s LevSel_Right | ||
Line 274: | Line 276: | ||
</asm> | </asm> | ||
− | Now the Sonic 1 level select will behave exactly like that of the one in Sonic 2 ( | + | Now the Sonic 1 level select will behave exactly like that of the one in Sonic 2 (Simon Wai prototype, except for night mode and split screen, those can be added manually if you get such a system working). Enjoy your alternative level select :) |
{{S1Howtos}} | {{S1Howtos}} | ||
− | [[Category:SCHG How-tos| | + | [[Category:SCHG How-tos|{{PAGENAME}}]] |
Revision as of 10:34, 5 June 2014
(Original guide by Kram1024)
You probably wonder why Sonic 2 Beta has that level select that looks almost like the Sonic 1 level select, and how Sonic 2 Nick Arcade prototype has one that is the Sonic 1 level select. Well, that is what we are going to make the one in Sonic 1 behave like.
Overview
First, let's look at an overview of what our level select code looks like normally in Sonic 1 (this is from the Hivebrain disassembly): <asm>
- ---------------------------------------------------------------------------
- Level Select
- ---------------------------------------------------------------------------
LevelSelect: move.b #4,($FFFFF62A).w bsr.w DelayProgram bsr.w LevSelControls bsr.w RunPLC_RAM tst.l ($FFFFF680).w bne.s LevelSelect andi.b #$F0,($FFFFF605).w ; is A, B, C, or Start pressed? beq.s LevelSelect ; if not, branch move.w ($FFFFFF82).w,d0 cmpi.w #$14,d0 ; have you selected item $14 (sound test)? bne.s LevSel_Level_SS ; if not, go to Level/SS subroutine move.w ($FFFFFF84).w,d0 addi.w #$80,d0 tst.b ($FFFFFFE3).w ; is Japanese Credits cheat on? beq.s LevSel_NoCheat ; if not, branch cmpi.w #$9F,d0 ; is sound $9F being played? beq.s LevSel_Ending ; if yes, branch cmpi.w #$9E,d0 ; is sound $9E being played? beq.s LevSel_Credits ; if yes, branch
LevSel_NoCheat: cmpi.w #$94,d0 ; is sound $80-$94 being played? bcs.s LevSel_PlaySnd ; if yes, branch cmpi.w #$A0,d0 ; is sound $95-$A0 being played? bcs.s LevelSelect ; if yes, branch
LevSel_PlaySnd: bsr.w PlaySound_Special bra.s LevelSelect
- ===========================================================================
LevSel_Ending: ; XREF: LevelSelect move.b #$18,($FFFFF600).w ; set screen mode to $18 (Ending) move.w #$600,($FFFFFE10).w ; set level to 0600 (Ending) rts
- ===========================================================================
LevSel_Credits: ; XREF: LevelSelect move.b #$1C,($FFFFF600).w ; set screen mode to $1C (Credits) move.b #$91,d0 bsr.w PlaySound_Special ; play credits music move.w #0,($FFFFFFF4).w rts
- ===========================================================================
LevSel_Level_SS: ; XREF: LevelSelect add.w d0,d0 move.w LSelectPointers(pc,d0.w),d0 ; load level number bmi.w LevelSelect cmpi.w #$700,d0 ; check if level is 0700 (Special Stage) bne.s LevSel_Level ; if not, branch move.b #$10,($FFFFF600).w ; set screen mode to $10 (Special Stage) clr.w ($FFFFFE10).w ; clear level move.b #3,($FFFFFE12).w ; set lives to 3 moveq #0,d0 move.w d0,($FFFFFE20).w ; clear rings move.l d0,($FFFFFE22).w ; clear time move.l d0,($FFFFFE26).w ; clear score rts
- ===========================================================================
LevSel_Level: ; XREF: LevSel_Level_SS andi.w #$3FFF,d0 move.w d0,($FFFFFE10).w ; set level number
PlayLevel: ; XREF: ROM:00003246�j ... move.b #$C,($FFFFF600).w ; set screen mode to $0C (level) move.b #3,($FFFFFE12).w ; set lives to 3 moveq #0,d0 move.w d0,($FFFFFE20).w ; clear rings move.l d0,($FFFFFE22).w ; clear time move.l d0,($FFFFFE26).w ; clear score move.b d0,($FFFFFE16).w ; clear special stage number move.b d0,($FFFFFE57).w ; clear emeralds move.l d0,($FFFFFE58).w ; clear emeralds move.l d0,($FFFFFE5C).w ; clear emeralds move.b d0,($FFFFFE18).w ; clear continues move.b #$E0,d0 bsr.w PlaySound_Special ; fade out music rts
- ===========================================================================
- ---------------------------------------------------------------------------
- Level select - level pointers
- ---------------------------------------------------------------------------
LSelectPointers: binclude misc\ls_point.bin align 2
- ---------------------------------------------------------------------------
- Level select codes
- ---------------------------------------------------------------------------
LevelSelectCode_J: binclude misc\ls_jcode.bin align 2
LevelSelectCode_US: binclude misc\ls_ucode.bin align 2
- ===========================================================================
</asm>
Notice anything here?
Button Fix, Part 1
A lot of stuff here we really do not need, as well as the fact that all buttons that are not the D-Pad seem to be used to play a sound or select a level. Let's fix that. <asm> LevelSelect: move.b #4,($FFFFF62A).w bsr.w DelayProgram bsr.w LevSelControls bsr.w RunPLC_RAM tst.l ($FFFFF680).w bne.s LevelSelect andi.b #$F0,($FFFFF605).w ; is A, B, C, or Start pressed? beq.s LevelSelect ; if not, branch move.w ($FFFFFF82).w,d0 cmpi.w #$14,d0 ; have you selected item $14 (sound test)? bne.s LevSel_Level_SS ; if not, go to Level/SS subroutine move.w ($FFFFFF84).w,d0 addi.w #$80,d0 tst.b ($FFFFFFE3).w ; is Japanese Credits cheat on? beq.s LevSel_NoCheat ; if not, branch cmpi.w #$9F,d0 ; is sound $9F being played? beq.s LevSel_Ending ; if yes, branch cmpi.w #$9E,d0 ; is sound $9E being played? beq.s LevSel_Credits ; if yes, branch
LevSel_NoCheat: cmpi.w #$94,d0 ; is sound $80-$94 being played? bcs.s LevSel_PlaySnd ; if yes, branch cmpi.w #$A0,d0 ; is sound $95-$A0 being played? bcs.s LevelSelect ; if yes, branch
LevSel_PlaySnd: bsr.w PlaySound_Special bra.s LevelSelect </asm>
We do not need the Japanese credits code, removed that junk. As for the levels, we want to start them with the start button but not exclusively just the start button, so an andi would be used there. Also, we want start to exit back to the Sega screen, and why not some nice music? Only B or C should play something on the sound test.
The results should look like this:
<asm> LevelSelect: move.b #4,($FFFFF62A).w bsr.w DelayProgram bsr.w LevSelControls bsr.w RunPLC_RAM tst.l ($FFFFF680).w bne.s LevelSelect move.w ($FFFFFF82).w,d0 cmpi.w #$14,d0 ; have you selected item $14 (sound test)? bne.s LevSelLevCheckStart; if not, go to Level/SS subroutine cmpi.b #$80,($FFFFF605).w ; is Start pressed? beq.s LevSelStartPress ; if true, branch cmpi.b #$20,($FFFFF605).w ; is B pressed? beq.s LevSelBCPress ; if not, branch cmpi.b #$10,($FFFFF605).w ; is C pressed? beq.s LevSelBCPress ; if not, branch bra.s LevelSelect
- ===========================================================================
LevSelLevCheckStart: ; XREF: LevelSelect andi.b #$80,($FFFFF605).w ; is Start pressed? beq.s LevelSelect ; if not, branch bra.s LevSel_Level_SS
LevSelBCPress: ; XREF: LevelSelect move.w ($FFFFFF84).w,d0 addi.w #$80,d0 cmpi.w #$94,d0 ; is sound $80-$94 being played? bcs.s LevSel_PlaySnd ; if yes, branch cmpi.w #$A0,d0 ; is sound $95-$A0 being played? bcs.s LevelSelect ; if yes, branch
LevSel_PlaySnd: bsr.w PlaySound_Special bra.s LevelSelect
LevSelStartPress: ; XREF: LevelSelect move.b #$00,$FFFFF600 jmp MainGameLoop ;go to sega screen
</asm>
Level Select Music Fix
That fixes the level select so that it runs levels in a Sonic 2 manner, but it doesn't fix the music. Let's do that now.
Find: <asm> Title_ClrVram: move.l d0,(a6) dbf d1,Title_ClrVram ; fill VRAM with 0
bsr.w LevSelTextLoad </asm>
and add under dbf d1,Title_ClrVram ; fill VRAM with 0, these lines: <asm> move.b #$81,d0 jsr PlaySound </asm> replace #$81 with your choice of song.
the result should look like: <asm> Title_ClrVram: move.l d0,(a6) dbf d1,Title_ClrVram ; fill VRAM with 0 move.b #$81,d0 jsr PlaySound bsr.w LevSelTextLoad </asm> Green Hill Zone music at the level select, how lovely. On the other hand, if you plan on using my Sonic 2 Sound Driver port, try using music number $91 and PlayMusic as opposed to PlaySound.
Button Fix, Part 2
As you already know, the A button is not yet fixed, time to fix that button:
First We will have to edit the "LevSel_SndTest" routine. $C (left and right) will not work for detecting an A button. We will need $4C (A/Left/Right) instead, so look in our function for: <asm> LevSel_SndTest: ; XREF: LevSelControls cmpi.w #$14,($FFFFFF82).w ; is item $14 selected? bne.s LevSel_NoMove ; if not, branch move.b ($FFFFF605).w,d1 andi.b #$C,d1 ; is left/right pressed? </asm>
and change it to read out: <asm> LevSel_SndTest: ; XREF: LevSelControls cmpi.w #$14,($FFFFFF82).w ; is item $14 selected? bne.s LevSel_NoMove ; if not, branch move.b ($FFFFF605).w,d1 andi.b #$4C,d1 ; is left/right/A pressed?
</asm> instead.
Now we can start working on adding the routine to handle the A button and increase the 16's ($10) part of the sound test:
locate: <asm> beq.s LevSel_NoMove ; if not, branch move.w ($FFFFFF84).w,d0 </asm>
and add below: <asm> btst #6,d1 ; is A pressed? bne.s LevSel_A ; if not, branch </asm>
Now locate: <asm> bcc.s LevSel_Right moveq #$4F,d0 ; if sound test moves below 0, set to $4F </asm>
and add this routine under it to add A button support to the level select: <asm> LevSel_A: btst #6,d1 ; is A button pressed? beq.s LevSel_Right ; if not, branch add.w #16,d0 ; add $10 to sound test </asm>
Now the Sonic 1 level select will behave exactly like that of the one in Sonic 2 (Simon Wai prototype, except for night mode and split screen, those can be added manually if you get such a system working). Enjoy your alternative level select :)