[N!NJA]

Hey All!

I decided to make my first post on Retro about a glitch I found in S3&K years ago, I haven't found anybody talking about and it's quite an interesting one. (Least for me.)

I have confirmed the glitch to work on consoles/emulators even compilations such as Mega Collection + etc.

To do the glitch, Grab S3&K, Doesn't matter if it's on real hardware or not.

Go to Angel Island Act 1 and enter the level select code, Upon hearing the chime proceed to the Sound Test like normal, Open Mushroom Hill Act 1 and enter Debug Mode.

Once you have done the above go back to the Sound Test, Load up Launch Base Act 2 with Debug Mode enabled, Select the S monitor and keep putting them up and down until the time reaches "1:80" now proceed to bounce on them all so you catch all the boxes at once and the game will glitch up, The music will continue to play but hitting Start resets the game and that's when the odd thing happens, Instead of S3&K you will now have S&K and none of the S3 levels will work.

I have recorded a video of the glitch in action, Please excuse the poor quality I am currently stuck on a 3G connection and haven't played emulators for years haha.

The video:

https://www.youtube....h?v=Gjq92X8OYJg

EDIT: I know "Debug" glitches/issues don't count but felt this should come to light and if staff wish to remove feel free, Thanks.

This post has been edited by N!NJA: 28 July 2014 - 06:10 PM

[GerbilSoft]

N!NJA, on 28 July 2014 - 05:22 PM, said:

Go to Angel Island Act 1 and enter the level select code, Upon hearing the chime proceed to the Sound Test like normal, Open Mushroom Hill Act 1 and enter Debug Mode.

Anything done in debug mode is *not* considered a "glitch", because you're screwing around with the game logic in a way that wasn't intended.

Restarting into S&K-only is a well-known aftereffect of crashes caused by using debug mode. I'm not sure about the specifics as to why it doesn't recognize that S3 is locked on, but suffice to say this isn't anything new.

EDIT: Actually, I'm wondering now. Do we have anything documented on the Wiki regarding debug mode crashes in S3&K? I can't seem to find anything on this subject.

This post has been edited by GerbilSoft: 28 July 2014 - 05:29 PM

[Dark Sonic]

Ah yes the ol disconnect Sonic 3 glitch by hitting a crap ton of S monitors. I've seen it, as I'm sure many have, it's just not worth reporting as debug glitches are just that, debug glitches. You can do lots of crazy stuff with debug mode.

If glitches are your thing, you should watch this playlist from a few years back. This guy found a ton of crazy things:

http://www.youtube.c...1596721403E0594

Edit: Ninja'd

This post has been edited by Dark Sonic: 28 July 2014 - 05:27 PM

[N!NJA]

Well I posted this as I hadn't seen anybody else mention it, Thought it might be of interest to some. Not much of a gamer these days more into collecting.

Thanks for saying though.

[iGamr]

I'm a bit surprised a bug this seemingly well-known doesn't appear to be documented anywhere, debug-mode or not. It'd certainly be nice to know what part of S-Monitor abuse causes the game to reset to Sonic & Knuckles, though, since being able to return to the title screen on a button press after the game becomes unresponsive sounds like it would be an intentional failsafe.

[N!NJA]

iGamr, on 28 July 2014 - 05:32 PM, said:

I'm a bit surprised a bug this seemingly well-known doesn't appear to be documented anywhere, debug-mode or not. It'd certainly be nice to know what part of S-Monitor abuse causes the game to reset to Sonic & Knuckles, though, since being able to return to the title screen on a button press after the game becomes unresponsive sounds like it would be an intentional failsafe.

Agreed it's why I decided to bring it into the light again, Was pretty shocked not to see it anywhere. As for the pressing Start to reset it does sound like a fail safe, I wonder if it's related to them splitting the game into two halves? Also makes me wonder what other issues can come up, Sadly I haven't played for ages, Guess it's time to play again research other odd things.

[Uberham]

'sup.

[Tiddles]

The reason you end up in S&K mode is just one side effect of the main result of this glitch, which is actually just severe but seemingly relatively predictable RAM corruption. In the Sonic 3 without Knuckles topic I mentioned a flag that's set at boot time to indicate whether you're playing S&K or S3&K - well, that gets set, so you get forced into S&K mode. The S3 data is still accessible; if you used PAR/GG codes to play as Tails, for instance, all his sprites would be there. It's just that the game is operating as S&K because of the flag.

A couple of other results of the memory corruption: the reason you can press start to get back to the title screen is because the game mode variable has been garbled, and you're now flagged as being in a demo, with invalid demo data being read from somewhere in the ROM. You'll also often crash upon reaching Hidden Palace if you can manage to continue a game without having your emeralds reset (the S&K title would clear them up) as your emerald data is also invalid and breaks the giant emerald objects.

I never dug up exactly where or why the code ends up in this mess, but I seem to have unintentionally fixed it in development versions of Sonic 3 Complete (nothing that's released yet). That suggests it's related to that bit where I looked at a certain branch of object spawning code and thought "Gosh, sure looks like that could overflow object RAM!" The next memory space after object RAM is the Kosinski decompression buffer, so I'm guessing it just overflows a little into that, which then causes the Kosinski decompressor to kick in and go nuts on the rest of RAM due to the garbage it's trying to process, but that's just an assumption.

[SpeedStarTMQ]

I've mentioned it before actually (I could scroll through my previous posts, but there's a lot). My brother does it on his Sonic Collection on his DS as a way of playing just Sonic and Knuckles. What happens is that Sonic goes out of control like he's in a demo and it causes the game to sorta crash and only loads up SK instead of S3&K.

Have never been able to get a good video though as recording from a DS sucks.

Nice that someone's finally documented it with a video though!

He also got debug working in S&K only. I read before that it's documented in the wiki S&K cheats section anyway.

This post has been edited by SpeedStarTMQ: 29 July 2014 - 04:43 AM

[JaredAFX]

SpeedStarTMQ, on 29 July 2014 - 04:37 AM, said:

My brother does it on his Sonic Collection on his DS as a way of playing just Sonic and Knuckles.

That's actually really creative. I personally would rather be playing S3&K as a whole, but that's still a very creative workaround! I know I never would have thought of doing that.

[nineko]

I wonder what's with this old thing being posted everywhere these days, just a few days ago someone else posted about it on SSRG.

[iGamr]

SpeedStarTMQ, on 29 July 2014 - 04:37 AM, said:

My brother does it on his Sonic Collection on his DS as a way of playing just Sonic and Knuckles.

Clever!

Tiddles, on 29 July 2014 - 01:35 AM, said:

The reason you end up in S&K mode is just one side effect of the main result of this glitch, which is actually just severe but seemingly relatively predictable RAM corruption. In the Sonic 3 without Knuckles topic I mentioned a flag that's set at boot time to indicate whether you're playing S&K or S3&K - well, that gets set, so you get forced into S&K mode. The S3 data is still accessible; if you used PAR/GG codes to play as Tails, for instance, all his sprites would be there. It's just that the game is operating as S&K because of the flag.

A couple of other results of the memory corruption: the reason you can press start to get back to the title screen is because the game mode variable has been garbled, and you're now flagged as being in a demo, with invalid demo data being read from somewhere in the ROM. You'll also often crash upon reaching Hidden Palace if you can manage to continue a game without having your emeralds reset (the S&K title would clear them up) as your emerald data is also invalid and breaks the giant emerald objects.

I never dug up exactly where or why the code ends up in this mess, but I seem to have unintentionally fixed it in development versions of Sonic 3 Complete (nothing that's released yet). That suggests it's related to that bit where I looked at a certain branch of object spawning code and thought "Gosh, sure looks like that could overflow object RAM!" The next memory space after object RAM is the Kosinski decompression buffer, so I'm guessing it just overflows a little into that, which then causes the Kosinski decompressor to kick in and go nuts on the rest of RAM due to the garbage it's trying to process, but that's just an assumption.

I wasn't expecting to get a decent explanation of this any time soon. Thanks for clearing all of that up.

[muteKi]

GerbilSoft, on 28 July 2014 - 05:26 PM, said:

N!NJA, on 28 July 2014 - 05:22 PM, said:

Go to Angel Island Act 1 and enter the level select code, Upon hearing the chime proceed to the Sound Test like normal, Open Mushroom Hill Act 1 and enter Debug Mode.

Anything done in debug mode is *not* considered a "glitch", because you're screwing around with the game logic in a way that wasn't intended.

Restarting into S&K-only is a well-known aftereffect of crashes caused by using debug mode. I'm not sure about the specifics as to why it doesn't recognize that S3 is locked on, but suffice to say this isn't anything new.

EDIT: Actually, I'm wondering now. Do we have anything documented on the Wiki regarding debug mode crashes in S3&K? I can't seem to find anything on this subject.

There are a ton though, depending on how bad a crash is, that it would probably take many pages to document. I think you can use the teleporter in debug in LRZ4 and crash to a reset that goes back to the title screen, for example.

[Nova]

A little unrelated but along the same lines... I came across a glitch that I have never been able to replicate, one that doesn't involve debug trickery or anything of the sort.

I was doing Marble Garden Zone Act 2, and had a fire shield equipped - after Eggman made the entire level quake and move up, I'm running all the way to the end of the 'rising ground' part before the boss... In the little cut-out section at the end where you just wait for it to finish if you make it quick enough, I held my turbo button in and started wildly fire-dashing left and right... Then suddenly the game seemed to warp me (as if I was entering a special stage or something) and before I knew it, the 2P character/level select screen was displayed with no option to select anything. Very, very weird and was only remedied by a game reset.

[Chibisteven]

In the RAM Addresses $FFAE & $FFAF with any value other than a zero is Sonic 3 not attached. You can alter this in emulators through PAR codes. Sonic 3 doesn't allow you to break S Monitors the way Sonic & Knuckles does. Debug mode glitches aren't technically glitches as you never encounter them during normal game play. They're some odd ball glitches that occur when playing Sonic 3 levels attached to Sonic & Knuckles that results in the game freezing during normal play. Anything that makes Sonic 3 crash can cause Sonic & Knuckles to reboot and act like the Sonic 3 is not attached (not always though).

The Genesis can't normally display more than certain amount of objects on a screen at a given time, so likely nobody ever noticed it or cared to fix it. No programmer in their right mind would put that many objects on screen to begin with. This is just simply a buffer overflow.

As for the turbo button glitch. Such a controller can let you pass the barrel in Carnival Night Zone (Act 2) with a chance you end up stuck in the wall or through the obstacle completely and on to the next level. It's likely the game was never tested with a such a controller and was an oversight in of itself based on collision based glitches in the game already being documented. I wouldn't advise someone using such a controller on a game that was not tested or developed for it, unless the developer mentions it or you're seriously handicapped and can't hit a button repeatedly enough.

This post has been edited by Chibisteven: 30 July 2014 - 09:56 PM