Sonic 1 title cards bug when Time Over

Hi:


I noticed a "little" bug here that I can't see what is causing it. When you die by Time Over (and lives still left, of course) when the fade out ends and the level is restarted, you can see the word ZONE in the middle of the screen for a little while, then it dissapear and the title cards appears as allways. Why the word ZONE appear there? any idea of how to fix it?


Thanks!

 

You really find the weirdest bugs in the most unexpected places, I'll probably ask you to help me debug my hack when it will near completion haha.


Anyway, is that bug supposed to be visible in the original game? I tried in green hill and couldn't see it.


That's when the first palette line fades in at the beginning of the level, right? Not when it fades out before the level restarts?


From a theoretical standpoint, it's kind of easy: the coordinates of the objects aren't set properly when it's created. Now, the question is why. Since before the object's creation the object ram is cleared, it shouldn't be related to objects previously in ram, so you'll have to look at the title card's code for the "zone" object.


Just in case though, you should try to find the address of the zone object's ram and check how its coordinates are changing at every step and at which primary/secondary routine counter.


By the way, did you modify the object?

 

It will be a pleasure, haha.

I tried again and it's weird. I can see this bug in original Sonic 1 in Fusion and in Regen but only in the REV01 version so... can be related with the bg deformation? :S

It's when the fade out of the TIME OVER screen ends, just when the screen is completely black and just before the title cards start to appear from the sides of the screen. The word ZONE appears for a little while near the middle of the screen and dissapear.

I think not, at least for long time

 

Hey, you're right:





But it only happens in the Japan version. Can't seem to get it to appear in the Europe version. But you said it's there for a while, but with me, it was only there for a frame. It was bloody hard getting a screenshot of it, even with slo-motion =P


One thing I did notice though, with both versions, is that if you're running out of time, the TIME will only flash red if you have no rings. If you have rings, it won't flash. But maybe people know that already; I don't hack Sonic 1 that I didn't notice 'til now.

 

@RHS: That's an old bug, there was a guide to fix it long ago, but I can't find it right now. You have to add a check for the 9 minutes in "Obj21_Flash2" (that's in the old disassembly not sure it's the same name in the last ones) and modify d0 (which stores the number of the frame to display) accordingly.


Now about that "zone" bug, in that revision there's a difference here (see the two parts with "Revision=0"):




Level_MainLoop:


bsr.w PauseGame


move.b #8,(v_vbla_routine).w


bsr.w WaitForVBla


addq.w #1,(v_framecount).w ; add 1 to level timer


bsr.w MoveSonicInDemo


bsr.w LZWaterFeatures


jsr ExecuteObjects


if Revision=0


else


tst.w (f_restart).w


bne GM_Level


endc


tst.w (v_debuguse).w ; is debug mode being used?


bne.s Level_DoScroll ; if yes, branch


cmpi.b #6,(v_player+obRoutine).w ; has Sonic just died?


bhs.s Level_SkipScroll ; if yes, branch


Level_DoScroll:


bsr.w DeformLayers


Level_SkipScroll:


jsr BuildSprites


jsr ObjPosLoad


bsr.w PaletteCycle


bsr.w RunPLC


bsr.w OscillateNumDo


bsr.w SynchroAnimate


bsr.w SignpostArtLoad


cmpi.b #id_Demo,(v_gamemode).w


beq.s Level_ChkDemo ; if mode is 8 (demo), branch


if Revision=0


tst.w (f_restart).w ; is the level set to restart?


bne.w GM_Level ; if yes, branch


else


endc


cmpi.b #id_Level,(v_gamemode).w


beq.w Level_MainLoop ; if mode is $C (level), branch


rts



So maybe you can try that.

 

Thought it would be well-known. I only just noticed it. Works fine in Sonic 2 so meh, I'm cool =P

 

Thank you guys. I already noticed the Time/Rings in red bug and it was fixed too long ago But thanks anyway. And yes, I said a little while... it can be only a frame. Thanks for checking and thanks for the screenshot.


About the possible fix... well, SpirituInsanum, I'm using the REV00 dissassembly where that bug shouldn't be happening and it's happening to me and the only thing I added of REV01 is the deformation BG data (from the Sonic Retro guide)....

 

Well, I tested what you said and you are right. Thanks SpirituInsanum.


I remember I changed that lines to make better the change between levels. Without this change the level loads the next level deformation when the actual level is fading, and that was ugly. Why can this be affecting to the word ZONE from the title cards only when TIME OVER? any idea of how avoid this?

 

Keep the first one but not the second, it should be enough to fix both the background and that bug.


I think it's because buildsprites is being used when it shouldn't, even though it's only one frame.

 

That's how already is in my hack. I have the first check only and the second removed.

 

Yup, I first noticed in 2008
This is how I fixed it: http://forums.sonicretro.org/index.php?showtopic=8815&view=findpost&p=464936

 

That bug is in my hack too. Any of you fixed it?

 

Sorry, no, I still can't fix this bug... it's too weird. As I said it happens in original Sonic 1 REV01 or if you fixed level transitions in REV00... Any help to try to fix this issue would be much appreciated.

 

I wanted to point this out that I haven't been able to fix it either. I ask though, what is the difference with fixing the level transitions? I tried reverting it back to the original method... of using the second check... I found NO issue myself, but perhaps I'm not noticing something.


I DID notice another bug though, that is unrelated to this one but I found it while investigating this one. TIME OVER blinks when the words join together. This lasts for one frame, and also occurs with GAME OVER.


EDIT: Tested and it also happens in the original. I have a fix if anyone cares to fix this SMALL unrelated bug. Go to _incObj/Game Over.asm and find this code.




Over_Move: ; Routine 2


moveq #$10,d1 ; set horizontal speed


cmpi.w #$120,x_pos(a0) ; has item reached its target position?


beq.s Over_SetWait ; if yes, branch


bcs.s Over_UpdatePos


neg.w d1


Over_UpdatePos:


add.w d1,x_pos(a0) ; change item position


bra.w DisplaySprite


; ===========================================================================


Over_SetWait:


move.w #720,anim_frame_duration(a0) ; set time delay to 12 seconds


addq.b #2,routine(a0)


bra.w DisplaySprite ; KoH additional line to prevent blinking.<==========


; ===========================================================================


Over_Wait: ; Routine 4


move.b (v_jpadpress1).w,d0


andi.b #btnABC,d0 ; is button A, B or C pressed?


bne.s Over_ChgMode ; if yes, branch


btst #0,mapping_frame(a0)


bne.s Over_Display


tst.w anim_frame_duration(a0) ; has time delay reached zero?


beq.s Over_ChgMode ; if yes, branch


subq.w #1,anim_frame_duration(a0) ; subtract 1 from time delay


bra.w DisplaySprite



You can easily see where I added the line to branch to DisplaySprite in the Over_SetWait: routine. It is the only one of the three without the branch, and without it, this causes the sprite to NOT appear for that frame, hence the flicker. It's that simple, but most might not even notice anyway.

 

Well in any case, it's still worth knowing, thanks for bringing that up =)

 

Nice, it also happens in Sonic 2 and Sonic 3 and Knuckles. Never noticed it. Nice find.


Being picky, but...

As you may of guessed, that rts is now useless as it's never going to be read. So you might as well delete that "rts" and save space.

 

Didn't even notice that I put that rts in there. It's out now.