Proto:Knuckles' Chaotix/Sonic Crackers

This is a sub-page of Proto:Knuckles' Chaotix.

File: Sonic Crackers (Prototype).bin (1 MB) (info)

Sonic Crackers (referred to as "Sonic Studium" in the ROM header) is a very early prototype of Knuckles' Chaotix, composed of different game engines swapped out using RAM coding. As the title may suggest, Sonic and Tails are the stars here, with the Chaotix cast nowhere to be found.

The available build, dated April 1, 1994 on the title screen, was released by MORGOTH on the Evil Empire BBS Belgium on June 15, 1995, making it one of the first substantial early prototypes to be shared online. The "19940401" date led to much debate on whether the title screen (a peculiar ASCII-art design that looks like it was thrown together in 5 minutes) or the ROM as a whole was a joke of some sort. The later discovery of several Chaotix prototypes in 2008, especially the 1207 build, proved that this was not the case. Also, "JUL.1994" can be seen when viewing the ROM through a hex editor, which may not mean much given that among the unused graphics in a June 1994 prototype of Yuu Yuu Hakusho: Makyou Toitsusen are sprites for Tails that are not in this build.

Much later, various Crackers graphics were used for Egg Gauntlet Zone in the 2013 version of Sonic 2, although the Zone was never normally accessible and both it and its assets were later removed.

General

Crackers is extremely incomplete and unpolished. However, the basic mechanics that serve as the basis of Chaotix are present at this point and similar to how they ended up in the final.

The player controls Sonic and Tails, both of whom were cut from the final game but not entirely scrapped - Sonic was retooled into Mighty the Armadillo by the 1207 prototype, as evidenced by the two's sprites being practically identical. Meanwhile, Tails was cut by the 1207 build, though his behavior was functional until the 0119 prototype.
The game is split between four playable levels: "Attractions", side-scrolling levels similar to those seen in previous Sonic games, and "Fields", overhead levels that have no collision detection. While Fields were cut by the 1207 prototype, Chaotix kept the "Attractions" name for its levels.
The primary game mechanic of Chaotix, the rubber band-like rings connecting the two playable characters, has been implemented at this point. While it's similar to how it ended up in the final, there are some key differences:
- The A, B, C, X, Y, and Z buttons all share the same functionality, causing one player to jump, the CPU to stop moving, and, if close enough, one player to pick up the other (and throw him). These functionalities were retained in Chaotix, though the jumping and holding buttons were separated and a recall button was added due to the controls being too complicated for one button. ^[1]
Pressing Start allows the player to move Sonic and Tails' X and Y positions with the D-Pad, much like the Debug Modes of prior Sonic games.
Pressing A + B + C + Start will reset the game. This functionality was kept in prototypes of Chaotix.
There are counters hidden below the viewable screen that contain debug info, such as the players' X and Y positions.
The Attractions are mostly devoid of objects; the only objects that the player can interact with are springs (which work as they normally do in Sonic games) and spikes (which cause the player to drop rings even though there are no rings to collect). Neither Sonic nor Tails can die, although the level will end once the in-game timer reaches a certain point.
Physics are extremely rudimentary; Sonic and Tails are not affected by gravity and can walk on walls and ceilings with no momentum.
Taking damage multiple times in succession will cause the player to go into a "dizzy" state where they are unable to move for a few seconds. This feature was removed in Chaotix, but the playable characters have unused sprites for it.
The characters' arms and Tails' tails will glitch sometimes when they are on slopes.
The soundtrack comprises early versions of Chaotix tracks. There are no sound effects in-game, though sound effects are present in the ROM.
The Sega logo screen is reused from Shinobi III. Chaotix features a unique one that shows off the 32X's scaling capabilities.

Levels

There are four playable levels, which are accessible either by pressing Start on "1P START" or "2P START" on the title screen or by using the "SELECT" menu.

Attraction Levels

World 1 Level

A circus/carnival-themed level which, rather than having a definite end, loops. The collision detection is glitchy and makes the floor difficult to walk on when entering the normal way, and each time the level loops the collision gets more and more broken. If you go far enough with Debug Mode, strips of garbage data spawn at the bottom of the level. You cannot die from falling into a pit, and are simply stuck there unless there is garbage data or you debug your way out.

Pressing Left while standing still will cause Sonic to fall through the floor, but not Tails. This is due to a typo in Sonic's code, which can be fixed by using the Pro Action Replay codes 00A3EE:B541 00A3F0:0241.

This level is thought to be a very early version of Chaotix's Speed Slider due to the similar aesthetic.

The music is an early version of Electoria. When the timer reaches 1 minute, the Game Over tune plays and the player is sent to the World 2 Field.

(Source: Sonic Retro)

World 2 Levels

An industrial-themed world. This is the World the game begins with from the title screen, likely done for testing purposes. Using the pause debug feature in this World will cause a vertical black bar to exist on the left side of the screen for the rest of the level. This is the only World with an obstacle which causes harm to the player (spikes), which in turn makes this the most complete World of this build.

There are four levels, the only differences between them being music and palette changes: Level 1 plays Walkin' and has a morning palette, Level 2 plays Hyper-Hyper and has a daytime palette, Level 3 plays Evening Star and has a sunset palette, and Level 4 plays Moonrise and has a nighttime palette. This lines up with the usage of these tracks in Chaotix's World Entrance, and indicates that the time of day feature was already planned at this point. Due to a vaguely similar aesthetic and the goal being to reach the top, this level is speculated to be a very early version of Techno Tower from Chaotix.

When the timer reaches 3 minutes, or when the top of the level is reached, the Game Over tune plays and the World 1 Field is entered.

World 2, Level 1
World 2, Level 2
World 2, Level 3
World 2, Level 4

(Source: Sonic Retro)

Worlds 3-7 and Premium 1-2

No work has been done on these. Trying to enter them shows the title card and plays the World 2 music for a few seconds before immediately giving you a Game Over and beginning a Field level. It is unknown what a "Premium" stage would have been like.

(Source: Sonic Retro)

Special Stage

Present on the Level Select menu, but no work has been done on this either. Unlike the above, however, selecting it causes the game to crash.

Field Levels

A pair of overhead stages which are very incomplete and have no collision detection. The music is the early version of Electoria also used in World 1.

To exit these stages, simply pause and press any button. The game will then load an Attraction of the World it is on.

Option

A simple sound test accessed from selecting "OPTION" on the title screen. This screen would remain unchanged in the Chaotix 1207 prototype, aside from the "OPTION" text being removed and the counter being positioned at the bottom-right of the screen.

Select

The game's Level Select. The menu text is somewhat misleading due to what is possibly an oversight: selecting the second item on the menu (ATTRACTION LV.1) will take you to the second level, selecting the third item (ATTRACTION LVL.2) will take you to the third level, and so forth.

Extra Characters

Under the hood, the game contains eight characters: Sonic, Tails, and six empty entries. It is thought that Knuckles, Charmy, Vector, Bomb, and Heavy were already planned at this point in development, as monitor sprites of the latter four characters rendered by the Genesis are used in the NPC select screen of the 1207 prototype, existing alongside unused monitors of Sonic, Tails, and Knuckles.

Unused World 2 Field Level Palette Cycle

The second Field level has a bug in one of its color palette cycles: The color palette cycle incorrectly uses color palette line 2, instead of 3 which is the foreground. However, by using the codes 008570:D43C 0085DC:D43E (or HWCT-BKXT H4CT-BK06), the intended effect can be restored.

Unused Chunks

There are a ton of unused stage chunks.

World 1

Some of these chunks, while unused in the level layout itself, appear as part of the garbage data found at the bottom of the level in the loopback.

07
0A
0B
0C
0E
17
19
1A
1C
1D
20
24
2A
2C
2D
30
38 - Appears in the loopback.
39 - Appears in the loopback.
3A - Appears in the loopback.
3C - Appears in the loopback.
3D - Appears in the loopback.
3F - Appears in the loopback.
42 - Appears in the loopback.
43 - Appears in the loopback.
45
47
48
49
4B
4C
50
51
52
53
56
57
58
5A
5C
5D
5E
60
61
63 - Appears in the loopback.
64
66
67
68
6A
6B
6C
6E
6F
70
71
72
73
74
75
76
78
79
7A
7B
7C
7D
7F
80
87
88
89
8A
8B
8C
8D
8E
8F
90
91
92
93
94
95
96
97
98
99
9A
9C
9D
9E
9F
A0
A1
A2
A3
A6
A7
A8
A9
AB
B0
B1
B4
B7
B9
BC
BE
C0
C1
C5
C8
C9
CA
CD
D2
D3
D8
D9
E2
E3

World 2

This stage has a lot more unused chunks than used ones.

Foreground

While the game also doesn't use tiles 30, 4A-4C, 4F, 50, 56, 58-5A, 60-62, A2-A5, AD, AF, B0, and B2, they are all blank and as such are not included here.

0E
0F
10
11
17
18
19
1A
1B
1C
1D
22
24
25
27
28
2A
2B
2D
2F
33
37
39
3B
3F
41
42
44
45
46
47
48
49
4D
4E
51
52
53
54
55
57
5B
5C
5D
5E
5F
63
64
65
66
67
68
69
6A
6B
6C
6D
6E
6F
70
71
72
73
74
75
76
77
78
79
7A
7B
7C
7D
7E
7F
80
81
82
83
84
85
86
87
88
89
8A
8B
8C
8D
8E
8F
90
91
98
99
9A
9B
9C
9D
9F
A0
A1
A6
A8
A9
AA
AB
AC
AE
B1
B6

Background

A sky with stars goes unused. Similar graphics for Amazing Arena exist in the final game, though they also go unused.

0C

Unused Sprites

To do:
The overdump contains art and audio samples from Teenage Mutant Ninja Turtles: Tournament Fighters.

Sonic Crackers contains a fair amount of unused sprites. Notably, many of Sonic's ended up getting repurposed for Mighty's in Chaotix.

Artwork	Name	Description
	Title Screen Font	Characters that are loaded into the VRAM for the title screen and menus but are not used, including a complete set of lowercase letters.
	Field Jumping Sprites	Jumping animations for Sonic and Tails in the Field levels. Sonic and Tails can't jump in the Fields, rendering these unused.
	Hold	Sonic and Tails' hold sprites, which go unused even though the hold mechanic has been implemented at this point. Notably, Sonic looks different from how Mighty would end up in his hold pose.
	Throwing	Like the hold sprites, these go unused even though throwing is present at this point. Sonic's sprites match up with Mighty's in the final, aside from Mighty turning his head more. Additionally, Tails' throw appears to show him stumbling, which lines up with him having the weakest throw in the other Chaotix prototypes he's still functional in.
	Wall Kick	Sonic performing a wall kick. While the ability is not coded in at this point, all the necessary sprites are present, indicating the mechanic was planned before Sonic became Mighty. Additionally, these sprites line up perfectly with Mighty's wall kick sprites (both the used and unused ones) in the final. The first sprite is based on an unused sprite from Sonic CD.
	Climbing	Sprites for hanging and climbing up a ledge. These are some of the few Sonic sprites that didn't make it into Chaotix to be adapted for Mighty; however, similar sprites for Knuckles and Vector exist. While the full animation exists for Sonic, Tails only has a hanging sprite.
	Flying/Tired	Tails' flying and tired sprites. The former is the same as in Sonic 2 minus the arm, while the latter sprites are unique. Modified versions of the tired sprites were later used in the Taxman/Stealth Retro Engine remakes of Sonic CD, 1, and 2.
	Sparkle Effects	Various sparkle effects that are loaded into VRAM during Attraction levels. The second palette line fits them best.
	Ring Sparkle	Sparkles normally seen when collecting rings. While rings are dropped when touching spikes, they cannot be collected.
	HUD Objects	Various HUD objects, including "Combi" and "Limits" (both of which remained through the final Chaotix). Given that Chaotix uses Limits for the Special Stage, the red objects on the right were most likely for Crackers' Special Stage (which is not present in this build).

Additionally, loaded in the second palette line is an alternate player palette that resembles colors for Knuckles. Sonic and Tails's arms use this line.

Hardware Issues

The game will crash on a real Mega Drive/Genesis console (or on certain emulators) if the player does not skip the Sega screen quickly enough or stays at the title screen for too long. This is due to the sound driver (which is held on and controlled by the Z80 sub-processor) - if it isn't given a music track ID to process quick enough after being set up, the game will fail.

The Easy Way

Open the ROM in a hex editor and go to offset $0052B7, then replace 21 05 1C 7E with 11 00 00 00.

The Hard Way

If, for whatever devilish reason you want to do this without modifying your ROM, you can do just that. Using the emulator BlastEm (specifically the latest nightly revision), as soon as you load up the game quickly press U to open the debugger and enter this prompt:

z80 set [$1C0A ] 0x81

Type c and press Enter to return back to the game. This will give Sonic Crackers' sound engine something to play to avoid crashing. Additionally, you can use your terminal of your choice and enter a argument to open the debugger as soon as the game loads.

When bypassing the crash stated above and obtaining access to the other selections in the menu, the game can crash in the Level Select option (named "SELECT"). When selecting the "PREMIUM1 - ATTRACTION" selection, the game crashes with a plain blue screen. The same happens when selecting "PREMIUM1 - FIELD", which will lead to the World 2 Field stage first, and will happen upon pausing and pressing A.

(Source: Sonic Retro)

The Game's Name

This needs some investigation.
Discuss ideas and findings on the talk page.
Specifically: see below

The ROM header came from an earlier build of Sonic Crackers. Was this confirmed?

The ROM header says the game is "Sonic Studium", as opposed to the "Sonic Crackers" on the title screen.

The header name should be "Sonic Stadium". This is due to a transliteration error into Japanese, where it became スタジアム (sutajiamu). Japanese has no "di" syllable, so "ji" is used in its place. The short vowel "a" in Japanese is pronounced as in the English word "father". As such, スタジ would sound very much like the English word "stud". An excerpt from the "Sonic Mars" script shows "Sonic Stadium" as a title under the "Future SEGA" products category, along with "Sonic 3+". The 1207 Chaotix prototype has unused graphics spelling out "Sonic Crackers S32X", indicating that the official name was changed after Mars was renamed to Super 32X.

Similarly, the name on the title screen (and by extension in the aforementioned Chaotix graphics) should be "Sonic Clackers". Japanese doesn't distinguish between Ls and Rs, and a result the name is a result of a cyclical transliteration error (Sonic Clackers -> ソニッククラッカー -> Sonic Crackers). This would also coincide with how actual clacker toys act like how Sonic and Tails do: a ball swings around from the force of another ball.

(Source: Sonic Retro)

Audio

Sounds

While the game doesn't use sound effects, there's a number of them in the ROM, mostly (if not entirely) brought over from previous games.

Sound ID	Audio	Notes
$A0		Sonic CD jumping SFX.
$A1		Sonic 1 end-of-Act/Special Stage "tally finished" SFX.
$A2		A sped-up version of the unused revving SFX from Sonic 3.
$A3		Sonic 1 bomb explosion SFX.
$A4		Sonic 1 skidding SFX.
$A5		Sonic 1 Ring loss SFX.
$A6		Sonic 1 Ring collect SFX. There is no left pan variant.
$A7		Sonic 3 Badnik destroyed SFX.
$A8		Sonic 3 spring SFX.
$A9		Sonic 1 checkpoint SFX.
$AA - $AF		Instantly plays a stop command. However, a voice is included, which is what's played here.

PCM

Present at 0x21672 and 0x22BEE are unused samples of a woman yelling "Let's go! Hey!". Where these samples would be used are a mystery; none of the music in Crackers or Chaotix uses vocal samples, and the only samples used are drums. These vocal samples were removed by the 1207 prototype.

Offset	Sound
0x21672
0x22BEE

(Source: PACHUKA, properly decoded by Beta Filter and Chimes)

Music

The music of Crackers mostly consists of early iterations of Chaotix songs. All of the tracks feature different percussion to their final counterparts - the Crackers versions utilize the Mega Drive's DAC channel for percussion, whereas the Chaotix versions were reworked to make use of the 32X's PWM channels instead, with several changes and embellishments made to the percussion in the process. This freed up the Mega Drive's 6th sound channel to be used for FM synthesis, allowing for some extra additions to each track.

Name	Sound ID	Notes
World 1/Field (Electoria)	81	The most different to its final counterpart. While the backing is very similar to the final version, the main melody was changed completely - the chorus of the Crackers version echoes the same basic melody as the other stage music present in this build, whereas the Chaotix version drops this in favor of a unique melody instead. The melody of the Crackers version at 0:44 is left unused in the data of the Chaotix music track.
World 2, Level 1 (Walkin')	82	As the Crackers DPCM samples have been replaced with the 32X's PWM samples (which allow for additional sounds in one channel), there's an additional maraca in the drumline. The lead melody has gained an additional echo channel which is hard to hear at first.
World 2, Level 2 (Hyper-Hyper)	83	Again, the Crackers DPCM samples have been replaced with the 32X's PWM samples, and the main melody uses 2 sound channels.
World 2, Level 3 (Evening Star)	84	The percussion track(s) were greatly changed to sound more dynamic.
World 2, Level 4 (Moonrise)	85	A few more instruments were added to the percussion track(s) to make the music sound more dynamic.
Game Over (Mechanical Dance)	86	Straight from Sonic 2. Completely replaced due to Sega not actually owning most of the Sonic 1/2 soundtrack and likely not licensing it for this project.