Basic Questions and Answers Thread

I'm using the dynamic tileset tutorial to see if my problem was solved but it's the same...
Is it impossible to edit a different palette for each act of the same zone in SonLVL?

 

I've tried adding Sonic 3's ring manager (provided by this tutorial) into Sonic 1 because S1's ring formations don't work right with Sonic 3's object manager which I also added. However, I experienced a problem I've never encountered before. What happens is that an error is caused when returning from the RingsManager_Setup subroutine and it seems like it happens between commands. And making it so the subroutine is part of the code that branches to it doesn't change anything.

The left is when I added "illegal" to the end of RingsManager_Setup and the right is the error I'm getting. Also, I rearranged the RAM addresses to their positions in Sonic 2 to make space if that's any help.

 

ProjectFM, it appears something has messed up the RAM completely, more precisely, it looks like a broken memory clear loop, that clears not what it should, or much more than it should. As the result, even the stack gets cleared and all return addresses are erased.
Which is why you're getting this error: since stack is totally zeroed, it returns to offset $000000 (startofrom) and the illegal instruction exception is triggered immediately as the processor's trying to execute data and not some proper code.

What also gets my attention is the subroutine name on the intentional crash at the left screenshot, loc_172b1. Out of curiosity, why does it happen to name an odd address? Was it provided by some tutorial you've used or did you come up with this random name to avoid confusion with stock Sonic 1 routines?

 

Thanks! I'll go see what's causing that problem.

I came up with label to replace the + used for the AS assembler. The each label was a number after the other, starting at loc_172AE.

Edit: The cause was that I didn't change the ClearRAM macro into code correctly.

 

Hi!
I've follow this guide and it's look like this:

http://image.noelshack.com/fichiers/2016/21/1464543554-sans-titre.png

Why the water surface and bubbles are like that?

I edit the pattern load cues. asm file but nothing happen...
Object pointers.asm isn't my issue i think..
What is the problem?

 

The problem is the pattern load cues are being overwritten. You need to make sure no other art is using the same RAM as the bubbles and stuff.

Now for my own:
Here is the code for the ring manager I ported to Sonic 1. For some reason, no rings are created despite all the code being the same as in the guide I used. Here's the code:

Code:

RingsManager:
    moveq    #0,d0
    move.b    ($FFFFFE17).w,d0
    move.w    RingsManager_States(pc,d0.w),d0
    jmp    RingsManager_States(pc,d0.w)
; ===========================================================================
; off_16F96:
RingsManager_States:
    dc.w RingsManager_Init-RingsManager_States
    dc.w RingsManager_Main-RingsManager_States
; ===========================================================================
; loc_16F9A:
RingsManager_Init:
    addq.b    #2,($FFFFFE17).w ; => RingsManager_Main
    bsr.w    RingsManager_Setup
    movea.l    ($FFFFE800+Rings_Space).w,a1
    lea    ($FFFFE800).w,a2
    move.w    ($FFFFF700).w,d4
    subq.w    #8,d4
    bhi.s    loc_16FB6
    moveq    #1,d4
    bra.s    loc_16FB6
; ===========================================================================

loc_16FB2:
    addq.w    #4,a1
    addq.w    #2,a2

loc_16FB6:
    cmp.w    (a1),d4
    bhi.s    loc_16FB2
    move.l    a1,($FFFFE800+Rings_Space).w
    move.w    a2,($FFFFF7A2).w
    addi.w    #$150,d4
    bra.s    loc_16FCE
; ===========================================================================

loc_16FCA:
    addq.w    #4,a1

loc_16FCE:
    cmp.w    (a1),d4
    bhi.s    loc_16FCA
    move.l    a1,($FFFFE800+Rings_Space+4).w
    rts
; ===========================================================================
; loc_16FDE:
RingsManager_Main:
    lea    ($FFFFEF80).w,a2
    move.w    (a2)+,d1
    subq.w    #1,d1
    bcs.s    loc_17014

loc_16FE8:
    move.w    (a2)+,d0
    beq.s    loc_16FE8
    movea.w    d0,a1
    subq.b    #1,(a1)
    bne.s    loc_17010
    move.b    #6,(a1)
    addq.b    #1,1(a1)
    cmpi.b    #8,1(a1)
    bne.s    loc_17010
    move.w    #-1,(a1)
    move.w    #0,-2(a2)
    subq.w    #1,($FFFFEF80).w

loc_17010:
    dbf    d1,loc_16FE8

loc_17014:
    movea.l    ($FFFFE800+Rings_Space).w,a1
    movea.w    ($FFFFF7A2).w,a2
    move.w    ($FFFFF700).w,d4
    subq.w    #8,d4
    bhi.s    loc_17028
    moveq    #1,d4
    bra.s    loc_17028
; ===========================================================================

loc_17024:
    addq.w    #4,a1
    addq.w    #2,a2

loc_17028:
    cmp.w    (a1),d4
    bhi.s    loc_17024
    bra.s    loc_17032
; ===========================================================================

loc_17030:
    subq.w    #4,a1
    subq.w    #2,a2

loc_17032:
    cmp.w    -4(a1),d4
    bls.s    loc_17030
    move.l    a1,($FFFFE800+Rings_Space).w
    move.w    a2,($FFFFF7A2).w
    movea.l    ($FFFFE800+Rings_Space+4).w,a2
    addi.w    #$150,d4
    bra.s    loc_1704A
; ===========================================================================

loc_17046:
    addq.w    #4,a2

loc_1704A:
    cmp.w    (a2),d4
    bhi.s    loc_17046
    bra.s    loc_17054
; ===========================================================================

loc_17052:
    subq.w    #4,a2

loc_17054:
    cmp.w    -4(a2),d4
    bls.s    loc_17052
    move.l    a2,($FFFFE800+Rings_Space+4).w
    rts
; ===========================================================================

loc_170BA:
    movea.l    ($FFFFE800+Rings_Space).w,a1
    movea.l    ($FFFFE800+Rings_Space+4).w,a2

loc_170D0:
    cmpa.l    a1,a2
    beq.w    return_17166
    movea.w    ($FFFFF7A2).w,a4
    cmpi.w    #$5A,$30(a0)
    bcc.w    return_17166
    cmpi.b    #1,($FFFFFE2C).w    ; does Sonic have a lightning shield?
    beq.s    Touch_Rings_NoAttraction    ; if not, branch
    move.w    8(a0),d2
    move.w    $C(a0),d3
    subi.w    #$40,d2
    subi.w    #$40,d3
    move.w    #6,d1
    move.w    #$C,d6
    move.w    #$80,d4
    move.w    #$80,d5
    bra.s    loc_17112
; ===========================================================================
  
Touch_Rings_NoAttraction:
    move.w    8(a0),d2
    move.w    $C(a0),d3
    subi.w    #8,d2
    moveq    #0,d5
    move.b    $16(a0),d5
    subq.b    #3,d5
    sub.w    d5,d3
    cmpi.b    #$4D,4(a0)
    bne.s    loc_17111
    addi.w    #$C,d3
    moveq    #$A,d5

loc_17111:
    move.w    #6,d1
    move.w    #$C,d6
    move.w    #$10,d4
    add.w    d5,d5

loc_17112:
    tst.w    (a4)
    bne.w    loc_1715C
    move.w    (a1),d0
    sub.w    d1,d0
    sub.w    d2,d0
    bcc.s    loc_1712A
    add.w    d6,d0
    bcs.s    loc_17130
    bra.w    loc_1715C
; ===========================================================================

loc_1712A:
    cmp.w    d4,d0
    bhi.w    loc_1715C

loc_17130:
    move.w    2(a1),d0
    sub.w    d1,d0
    sub.w    d3,d0
    bcc.s    loc_17142
    add.w    d6,d0
    bcs.s    loc_17148
    bra.w    loc_1715C
; ===========================================================================

loc_17142:
    cmp.w    d5,d0
    bhi.w    loc_1715C

loc_17148:
    btst    #5,$2B(a0)
    bne.s    AttractRing
  
loc_17148_cont:
    move.w    #$604,(a4)
    bsr.s    loc_17168
    lea    ($FFFFEF82).w,a3

loc_17152:
    tst.w    (a3)+
    bne.s    loc_17152
    move.w    a4,-(a3)
    addq.w    #1,($FFFFEF80).w

loc_1715C:
    addq.w    #4,a1
    addq.w    #2,a4
    cmpa.l    a1,a2
    bne.w    loc_17112

return_17166:
    rts
; ===========================================================================

loc_17168:
    subq.w    #1,($FFFFF712).w
    bra.w    CollectRing
; ===========================================================================

AttractRing:
    movea.l    a1,a3
    jsr    SingleObjLoad
    bne.w    AttractRing_NoFreeSlot
    move.b    #$4C,(a1)
    move.w    (a3),8(a1)
    move.w    2(a3),$C(a1)
;    move.w    a0,parent(a1)
    move.w    #-1,(a4)
    rts  
; ===========================================================================
  
AttractRing_NoFreeSlot:
    movea.l    a3,a1
    bra.s    loc_17148_cont
; ===========================================================================

loc_17178:
    movea.l    ($FFFFE800+Rings_Space).w,a0
    move.l    ($FFFFE800+Rings_Space+4).w,d7
    sub.l    a0,d7
    bne.s    loc_17186
    rts
; ===========================================================================

loc_17186:
    movea.w    ($FFFFF7A2).w,a4
    lea    ($FFFFF700).w,a3

loc_1718A:
    tst.w    (a4)+
    bmi.w    loc_171EC
    move.w    (a0),d3
    sub.w    (a3),d3
    addi.w    #$80,d3
    move.w    2(a0),d2
    sub.w    4(a3),d2
    andi.w    #$7FF,d2
    addi.w    #8,d2
    bmi.s    loc_171EC
    cmpi.w    #$F0,d2
    bge.s    loc_171EC
    addi.w    #$78,d2
    lea    (Map_Obj25).l,a1
    moveq    #0,d1
    move.b    -1(a4),d1
    bne.s    loc_171C8
    move.b    ($FFFFFEC3).w,d1

loc_171C8:
    add.w    d1,d1
    adda.w    (a1,d1.w),a1
    move.b    (a1)+,d0
    ext.w    d0
    add.w    d2,d0
    move.w    d0,(a2)+
    move.b    (a1)+,(a2)+
    addq.b    #1,d5
    move.b    d5,(a2)+
    move.w    (a1)+,d0
    addi.w    #$247C,d0
    move.w    d0,(a2)+
    addq.w    #2,a1
    move.w    (a1)+,d0
    add.w    d3,d0
    move.w    d0,(a2)+

loc_171EC:
    addq.w    #4,a0
    subq.w    #4,d7
    bne.w    loc_1718A
    rts
; ===========================================================================

loc_171F8:
    lea    ($FFFFF700).w,a3
    move.w    #$78,d6
    movea.l    ($FFFFE800+Rings_Space).w,a0
    move.l    ($FFFFE800+Rings_Space+4).w,d7
    movea.w    ($FFFFF7A2).w,a4
    sub.l    a0,d7
    bne.s    loc_17224
    rts
; ===========================================================================

loc_17224:
    tst.w    (a4)+
    bmi.w    loc_17288
    move.w    (a0),d3
    sub.w    (a3),d3
    addi.w    #$80,d3
    move.w    2(a0),d2
    sub.w    4(a3),d2
    andi.w    #$7FF,d2
    addi.w    #$88,d2
    bmi.s    loc_17288
    cmpi.w    #$170,d2
    bge.s    loc_17288
    add.w    d6,d2
    lea    (Map_Obj25).l,a1
    moveq    #0,d1
    move.b    -1(a4),d1
    bne.s    loc_17260
    move.b    ($FFFFFEC3).w,d1

loc_17260:
    add.w    d1,d1
    adda.w    (a1,d1.w),a1
    move.b    (a1)+,d0
    ext.w    d0
    add.w    d2,d0
    move.w    d0,(a2)+
    move.b    (a1)+,d4
    move.b    byte_17294(pc,d4.w),(a2)+
    addq.b    #1,d5
    move.b    d5,(a2)+
    addq.w    #2,a1
    move.w    (a1)+,d0
    addi.w    #$235E,d0
    move.w    d0,(a2)+
    move.w    (a1)+,d0
    add.w    d3,d0
    move.w    d0,(a2)+

loc_17288:
    addq.w    #4,a0
    subq.w    #4,d7
    bne.w    loc_17224
    rts
; ===========================================================================
; unknown
byte_17294:
    dc.b   0,0    ; 1
    dc.b   1,1    ; 3
    dc.b   4,4    ; 5
    dc.b   5,5    ; 7
    dc.b   8,8    ; 9
    dc.b   9,9    ; 11
    dc.b  $C,$C    ; 13
    dc.b  $D,$D    ; 15
; ===========================================================================

RingsManager_Setup:
    lea    ($FFFFE800).w,a1
    moveq    #0,d0
    move.w    #Rings_Space/4-1,d1

loc_172AE:                ; CODE XREF: h+33Cj
    move.l    d0,(a1)+
    dbf    d1,loc_172AE

    lea    ($FFFFEF80).w,a1
    move.w    #$1F,d1

loc_172AF:
    move.l    d0,(a1)+
    dbf    d1,loc_172AF

    moveq    #0,d5
    moveq    #0,d0
    move.w    ($FFFFFE10).w,d0
    lsl.b    #6,d0
    lsr.w    #4,d0
    lea    (RingPos_Index).l,a1
    move.w    (a1,d0.w),d0
    lea    (a1,d0.w),a1
    move.l    a1,($FFFFE800+Rings_Space).w
    addq.w    #4,a1
    moveq    #0,d5
    move.w    #(Max_Rings-1),d0

loc_172B0:
    tst.l    (a1)+
    bmi.s    loc_172B1
    addq.w    #1,d5
    dbf    d0,loc_172B0

loc_172B1:
    move.w    d5,($FFFFF712).w
    move.w    #0,($FFFFF716).w    ; no idea what this is
    rts

Could anyone figure out the problem? I rearranged the RAM addresses to their positions in Sonic 2 to make space and $FFFFF7A2 is used for Ring_start_addr_RAM. Also, the code is loaded under Level_LoadObj and Level_MainLoop. Lastly, I made sure the addresses are correct when loading the ring positions.

 

And how can i know what is the good RAM adresse to use?

 

Open the hack with Regen, load (completely) the level you want, open the VDP Debugger and search in the window on the left for empty and/or leftover tiles from previous levels/screens.

 

I'll probably look like a dick but what is "Regen"?

 

An emulator with fairly extensive debugging capabilities.

 

Sorry for the doube post, but now i have Regen and i'm in my level. But the VDP Debugger dont work...

 

"Doesn't work" is the least helpful thing you could possibly say when describing an error. How do you expect it to work? How does it not perform to your expectations? For all I know, the VDP debug window option is greyed out, or the window just displays blank, or the VRAM contents is wrongly displaying empty.

 

VDP Debug in "Tools" is Grey (sorry!)

 

You're using the standard version of Regen; you need the debugging version, "Regen 0.972D".

 

Ok thank you i'll take it!

Ok i have this http://image.noelshack.com/fichiers/2016/21/1464550528-sans-titre.png!
I don't understand anything, i try to understand by myself but when i want to look at the offset tile list at left, the offset go until 0x05DC...

EDIT: Sorry again for double posting, it's not my intention!

 

Sorry for double (triple) posting!

EDIT: my problem is resolved

 

EDIT: It appears I'm late and Ashuro has sorted out this issue on his own.
Since the issue above has been resolved already and contents of the above post have been removed, my reply doesn't make much sense now.
But I'd still like to keep if for a while, albeit under the spoiler tag. Perhaps, Ashuro also will find the analysis of his code I provided helpful.

Spoiler

Ashuro, Sonic always goes to the right, because your code always sets $14(a0) to $C00, regardless Sonic's direction. You are also doing some odd calculations based on the $14(a0) value in register D0, but you don't seem to use them anywhere, so they have no effect eventually.

To make it even easier for you, let's see how the processor "sees" this code, and what you'll get once it's executed:

Code:

; Let $14(a0) = X

B_Direction:
        btst    #0,$22(a0)              ; test bit #0 of $22(a0)
        beq.s   B_Direction2            ; if bit is clear, branch
        neg.w   $14(a0)                 ; $14(a0) = -X

B_Direction2:
        move.w  #1,$10(a0)              ; $10(a0) = 1
        move.w  #$0C00,$14(a0)          ; $14(a0) = $C00
        move.w  $14(a0),d0              ; d0 = $14(a0) = $C00 ...
        subi.w  #$800,d0                ;   ... + $800 = $400
        add.w   d0,d0                   ;   ... * 2 = $800
        andi.w  #$1F00,d0               ;   ... & $1F00 = $800
        addi.w  #$2000,d0               ;   ... + $2000 = $2800

B_End:
        rts ; return

; By the end of code we get:
;       $14(a0) = $C00
;            d0 = $2800 (UNUSED!)

$14(a0) is always $C00, because

Code:

        move.w  #$0C00,$14(a0)          ; $14(a0) = $C00

is executed anyways.

To be more specific, you are checking, whether Sonic is facing right or not, here:

Code:

        btst    #0,$22(a0)  

1. If Sonic's facing right, then ...
   
   Code:

           beq.s  B_Direction2  

   ... jumps to the location pointed by B_Direction2 and the processor will execute the following instructions:
   
   Code:

           move.w  #1,$10(a0)              ; $10(a0) = 1
           move.w  #$0C00,$14(a0)          ; $14(a0) = $C00
           move.w  $14(a0),d0              ; d0 = $14(a0) = $C00 ...
           subi.w  #$800,d0                ;   ... + $800 = $400
           add.w   d0,d0                   ;   ... * 2 = $800
           andi.w  #$1F00,d0               ;   ... & $1F00 = $800
           addi.w  #$2000,d0               ;   ... + $2000 = $2800
           rts 
   

   In this case, $14(a0) is set to $C00.
   
   
2. If Sonic's facing left, then ...
   
   Code:

           beq.s  B_Direction2  

   ... won't jump, the processor will execute the underlying instructions. So it will execute the following:
   
   Code:

           neg.w   $14(a0)                 ; $14(a0) = -X
           move.w  #1,$10(a0)              ; $10(a0) = 1
           move.w  #$0C00,$14(a0)          ; $14(a0) = $C00
           move.w  $14(a0),d0              ; d0 = $14(a0) = $C00 ...
           subi.w  #$800,d0                ;  ... + $800 = $400
           add.w  d0,d0                  ;  ... * 2 = $800
           andi.w  #$1F00,d0              ;  ... & $1F00 = $800
           addi.w  #$2000,d0              ;  ... + $2000 = $2800
           rts
   

   In this case, again, $14(a0) is set to $C00.
   So the extra NEG instruction you're doing in case Sonic's facing left has no effect, as the value gets overwritten anyways.

 

Thank for this lesson, i learn more about asm everydays

I want to post it, i have resolved my problem like this:
;======================================================================================
B_Direction:
move.w #1,$10(a0) ; force X speed to nonzero for camera lag's benefit
move.w #$0C00,$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,(v_cameralag).w
btst #0,$22(a0)
beq.s B_Direction2
neg.w $14(a0)

B_Direction2:
bclr #7,$22(a0)
move.w #$BC,d0
jsr (PlaySound_Special).l
bra.w B_End
;======================================================================================

 

ProjectFM, are you sure not a single ring is loaded? Your the code seems okay at the first glace, I'm sure it does at least something right, provided you feed it with the correct data and it doesn't crash or cause major memory corruption.
Another good question is... do you actually display the rings?

In stock Sonic 1, creating an object and calling DisplaySprite inside it is pretty much the only way display a sprite. The object requested will be later processed by the BuildSprites routine, it's sprite mappings will be converted and sent to the VDP's sprite buffer.

In Sonic 2, they expanded BuildSprites to handle more than just some plain objects. First off, they added child sprites system, so a single object can display and move multiple sprite frames at once (used for invincibility stars and starpost stars). Second off, they hardcoded HUD displaying into the BuildSprites itself (so HUD didn't have to occupy an object slot anymore, which saves some memory).
And last but not least, they separated rings from the objects system, introducing the rings manager, which handled rings more effectively in terms of memory and processor resources (because wasting the entire object slot on a single ring isn't a good use for rather slow and complex objects system). Since rings manager doesn't use proper object slots to keep rings, they have to be displayed (converted to sprites) on their own.

So, in Sonic 2 and Sonic 3, there's a part of rings manager that handles rings displaying. Check out BuildSprites in Sonic 2, it jumps to BuildRings right in the beginning, which, obviously, build all the rings sprites.
So, I ask you again... do you actually display the rings?

In the code you provided, there are actually subroutines that handle sprite displaying: loc_17178, loc_171F8 and loc_1720E. There are never referenced to in the code, which is correct. You should call them in BuildSprites.
You have specified that you jump to the RingsManager subroutine somewhere, but do you actually call the ones I listed?
These routine names come from Sonic 2, they are called BuildRings, BuildRings_P1 and BuildRings_P2 respectively in the newer disassemblies. So if you apply this guide in Sonic 2, there's no problem: you'll just overwrite the existing routines and they'll still be called from BuildSprites. But in Sonic 1, the won't.

Make sure you call them where appropriate, make sure they are compatible with Sonic 1's BuildSprites.

 

That must be the problem. Thanks! I'll try adding that.

Edit: I added the branch to loc_17178 along with the flag for if the level has started but now, the branch back to loc_1718A is causing an address error.

Edot2: Nevermind. I made BuildSprites branch to the wrong place.