Actions

SCHG

Sonic 3

From Sonic Retro

This is the Sonic Community Hacking Guide for Sonic the Hedgehog 3.

Start position array

These locations dictate where Sonic starts in the level. This is useful if you edited the level layout. You wouldn't want Sonic to fall from the sky or buried six feet under would you? That would look unprofessional.

The format is: XXXX YYYY, where:

  • XXXX = X position
  • YYYY = Y position

Here is a table for the offsets of each position:

Zone Act 1 Act 2
AIZ $5E018 $5E01C
HCZ $5E020 $5E024
MGZ $5E028 $5E02C
CNZ $5E030 $5E034
ICZ $5E040 $5E044
LBZ $5E048 $5E04C
FBZ $5E038 $5E03C
LRZ $5E060 $5E064

Boss Hitcounts

  • $469A3 - Angel Island Mini-boss
  • $47159 - Angel Island Boss
  • $47E07 - Hydrocity Mini-boss
  • $48D6F - Hydrocity Boss
  • $5639B - Marble Garden Mini-boss
  • $4A149 - Marble Garden Boss
  • $4C037 - CNZ Boss
  • $4E439 - Ice Cap Mini-boss
  • $4ED65 - IceCap Boss
  • $4F4A1 - Launch Base Mini-boss
  • $5044F - Launch Base Cannon Boss
  • $4F9D9 - Launch Base Rocket Boss
  • $50CF9 - Final Boss
  • $4DBCB - Flying Battery Boss (Unused, obviously)

Palette Editing

Usually, it's not really necessary to edit a palette in hex. Palette editors give you instant feedback for each RGB value, and the palette can be easily saved as a separate binary and reimported into the ROM. However, it is sometimes desirable or necessary to do it in hex, and it can't hurt to know how it's done.

These are the ROM offsets of the palettes in Sonic 3, as listed by HivePal:

Offset Name
$291A Angel Island Act 1 Cycle #1
$293A Angel Island Act 1 Cycle #2
$29BA Angel Island Act 1 Cycle #3
$2A1A Angel Island Act 1 Cycle #4
$2A4A Angel Island Act 2 Cycle #1
$2A6A Angel Island Act 2 Cycle #2
$2A9A Angel Island Act 2 Cycle #3
$2ACA Angel Island Act 2 Cycle #4
$2B32 Hydrocity Act 1 Cycle
$2B52 Carnival Night Cycle #1
$2BB2 Carnival Night Cycle #2
$2C32 Carnival Night Cycle #3
$2C66 Carnival Night Cycle #4
$2CA6 Carnival Night Cycle #5
$2D06 Carnival Night Cycle #6
$2D86 Carnival Night Cycle #7
$2DFA Icecap Cycle #1
$2E3A Icecap Cycle #2
$2E82 Icecap Cycle #3
$2E9A Icecap Cycle #4
$2EDA Launch Base Act 1 Cycle
$2EEC Launch Base Act 2 Cycle
$2EFE Lost Level 09 Act 1 Cycle #1
$2F7E Lost Level 09 Act 1 Cycle #2
$2FA2 2P Level - Balloon Park Cycle #1
$2FB4 2P Level - Balloon Park Cycle #2
$3032 2P Level - Desert Palace Cycle
$3082 2P Level - Endless Mine Cycle #1
$30BE 2P Level - Endless Mine Cycle #2
$31C2 Super Sonic
$31FE Super Sonic Underwater
$323A Super Sonic Underwater
$3C78 Sega Logo #1
$3CF8 Sega Logo #2
$3D08 Intro Frame #1
$3D48 Intro Frame #2
$3D88 Intro Frame #3
$3DC8 Intro Frame #4
$3E08 Intro Frame #5
$3E48 Intro Frame #6
$3E88 Title Screen
$3FD4 Title Screen Cycle
$5092 2P Level - Knuckles
$70BC Level Select Menu - EHZ Icon
$70DC Level Select Menu - MZ Icon
$70FC Level Select Menu - HTZ Icon
$711C Level Select Menu - HPZ Icon
$713C Level Select Menu - OOZ Icon
$715C Level Select Menu - MCZ Icon
$717C Level Select Menu - CNZ Icon
$719C Level Select Menu - CPZ Icon
$71BC Level Select Menu - ARZ Icon
$71DC Level Select Menu - SCZ Icon
$71FC Level Select Menu - WFZ Icon
$721C Level Select Menu - DEZ Icon
$723C Level Select Menu - Special Stage Icon
$725C Level Select Menu - X Icon
$727C Level Select Menu - Sound Test Icon
$7A26 Special Stage - Sonic and Tails
$7A66 Special Stages
$7AA6 Special Stage 1
$7ACC Special Stage 2
$7AF2 Special Stage 3
$7B18 Special Stage 4
$7B3E Special Stage 5
$7B64 Special Stage 6
$7B8A Special Stage 7
$7BB0 Special Stage 8
$A55E 2P Menu - Sonic and Tails
$A57E 2P Menu - Knuckles
$A59E 2P Menu - Unselected Portraits
$A5BE 2P Menu - ALZ Portrait
$A5DE 2P Menu - BPZ Portrait
$A5FE 2P Menu - CGZ Portrait
$A61E 2P Menu - DPZ Portrait
$A63E 2P Menu - EMZ Portrait
$BBB6 Data Select - Sonic/Tails/Knuckles/Emeralds
$BBF6 Data Select - Sonic Portrait
$BC16 Data Select - Super Sonic Portrait
$BC36 Data Select - AIZ Portrait
$BC56 Data Select - HCZ Portrait
$BC76 Data Select - MGZ Portrait
$BC96 Data Select - CNZ Portrait
$BCB6 Data Select - FBZ Portrait (Unused)
$BCD6 Data Select - ICZ Portrait
$BCF6 Data Select - LBZ Portrait
$236AC Red Balls Debug Mode Item
$2D3BE Special Stage Results
$4160A Ending - Credits
$4168A Ending - Knuckles and Eggman
$457AE Knuckles
$457CE ###
$4580E Carnival Night Lights Off
$45E86 Angel Island Act 1 Intro - Emeralds
$47092 Angel Island Act 1 Boss
$47CD6 Angel Island Act 2 Boss
$48C9A Hydrocity Act 1 Boss
$49D52 Hydrocity Act 2 Boss
$4B588 Marble Garden Act 2 Boss
$4BF70 Carnival Night Act 1 Boss
$4C91E Carnival Night Act 2 Boss
$4D520 Flying Battery Act 1 Boss
$4DB80 Flying Battery Act 2 Boss
$4EBC2 Icecap Act 2 Boss
$4F444 Icecap Act 1 Boss
$4F98C Launch Base Act 1 Boss
$503EE Launch Base Act 2 Triplet Boss
$50C8A Launch Base Act 2 Cannonball Boss
$520DC Launch Base Act 2 Final Boss
$5211C Ending - Sonic
$5213C Ending - Tails
$5215C Ending - Super Sonic
$8C234 Sonic and Tails
$8C274 Level Select Menu
$8C314 Angel Island Act 1
$8C374 Angel Island Act 1 Intro
$8C3D4 Angel Island Act 2
$8C494 Angel Island Act 1 Underwater
$8C434 Angel Island Act 2 FBZ Sequence
$8C514 Angel Island Act 2 Underwater
$8C594 Hydrocity Act 1
$8C654 Hydrocity Act 1 Underwater
$8C5F4 Hydrocity Act 2
$8C6D4 Hydrocity Act 2 Underwater
$8C754 Marble Garden
$8C7B4 Carnival Night
$8C814 Carnival Night Underwater
$8C894 Icecap Act 1
$8C8F4 Icecap Act 2
$8C954 Icecap Act 2 Underwater
$8C9D4 Launch Base Act 1
$8CA34 Launch Base Act 2
$8CA94 Launch Base Act Underwater
$8CB74 2P Level - Azure Lake
$8CBD4 2P Level - Balloon Park
$8CC94 2P Level - Chrome Gadget
$8CC34 2P Level - Desert Palace
$8CCF4 2P Level - Endless Mine
$8CD54 Bonus Stage
$A943C Mushroom Hill Act 1
$A949C Mushroom Hill Act 2
$A909C Flying Battery Act 1
$A90FC Flying Battery Act 2
$A94FC Sandopolis Act 1
$A955C Sandopolis Act 2
$A967C Lava Reef Act 1
$A96DC Lava Reef Act 2
$A9CDC Lava Reef Act 2 Boss
$A9D3C Hidden Palace
$A973C Sky Sanctuary Act 1
$A979C Sky Sanctuary Act 2
$A98BC Death Egg Act 1
$A991C Death Egg Act 2
$A9D9C Death Egg Act 2 Boss
$A997C The Doomsday
$164896 Marble Garden Act 2 - Day to Night #1
$164916 Marble Garden Act 2 - Day to Night #2
$164996 Marble Garden Act 2 - Day to Night #3
$164A16 Marble Garden Act 2 - Day to Night #4
$19D262 Data Select - Background
$19D282 2P Menu - Background

For information about the palette format, see Megadrive palette.

Object Pointer List

Sonic 3's Object Pointer List is different from the one used when locked on to Sonic & Knuckles. Many of the objects with low numbered ID's may match, but it's totally re-ordered later on.

ID # Description
00 Ring
01 Monitor
02 Collision Plane Switcher
03 Large tree from AIZ 1 (the one right leading up to the miniboss cutscene)
04 Crumbling platforms from AIZ and ICZ
05 Rock from AIZ, LRZ and EMZ
06 Vine which slides down a rope from AIZ 1
07 Spring
08 Spikes
09 Tree bark from AIZ 1. Used only by the tree at coordinates $2F78 and $318. The only purpose this serves is that the bombers passing through the sky are masked by it instead of appearing over the tree
0A Rope peg from AIZ 1, at the end of the pulley which you ride down
0B Red revolving spheres
0C Swinging vine from AIZ
0D Breakable Wall
0E Ridge from AIZ, MHZ, SOZ and LRZ which launches player up and forces twirl
0F Collapsing platform/bridge/ledge
10 Tube transporters from LBZ
11 Floating platform from LBZ
12 Platform in LBZ which moves up when a flag is set and then returns to its original position when the flag is cleared (unused)
13 Exploding trigger from LBZ which causes bridges to change positions
14 Bridge from LBZ which changes position when its corresponding trigger explodes
15 Launcher from LBZ which thrusts the player forward at a high speed
16 Flame thrower from LBZ
17 Hooked ride from LBZ
18 Cup elevator from LBZ
19 Pole attached to cup elevator from LBZ
1A ??
1B Smashable mini-pillar from LBZ
1C ??
1D Platform from LBZ which you can hang on to at the bottom (unused)
1E Launcher from LBZ 2 which thrusts player upward and forces a spin
1F Hook from LBZ which transports player up
20 Smashing pillar from MGZ, smashing spikes from LBZ
21 Laser-shooting gate from LBZ
22 Siren from LBZ 1
23 ??
24 Looping pipes from LBZ/pipes from LRZ which eject the player out at high speed
25 Ring (unused slot)
26 Tunnel entrance/exit (forces spin)
27 ??
28 Invisible barrier (the GTGT blocks in debug mode)
29 Disappearing platform from AIZ
2A Breakable floor piece from various levels
2B Flipping stairway from AIZ
2C Collapsing log bridge from AIZ
2D Falling logs from AIZ
2E Spiked rotating log from AIZ 2
2F Various non-animated still sprites from levels. Includes stuff like bridge posts from AIZ, waterfalls from HCZ, mini-towers from LBZ, etc
30 Various animated still sprites from levels. Includes stuff like fire pieces from AIZ 2, the rotating pieces on which bricks travel in SOZ, special lava pieces from LRZ, etc
31 Rotating cylinders from LBZ
32 Drawbridge from AIZ 2 (the one which Knuckles destroys after the boss fight)
33 Button
34 Starpole
35 Plants in foreground in AIZ 1
36 Breakable bar from HCZ
37 The vertical water stream from HCZ 1 which moves forward when you break the first barrier
38 Propelling fans from HCZ and CGZ
39 Large fan from HCZ which propels player forward
3A Hand launcher from HCZ
3B Wall in HCZ 1 from which a stream of water gushes out, breaking bricks along the way
3C Door (used in HCZ, CNZ and DEZ)
3D Spring from FBZ 2 which moves up and down. Only used once in entire game
3E Conveyor belt from HCZ
3F Spike on HCZ conveyor belt
40 Single block from HCZ. Usually pieced together to form horizontal groups
41 Balloon from CNZ
42 Cannon from CNZ
43 Platform from CNZ which falls when you stand on it and rises when you jump
44 Trapdoor in CNZ from which player is ejected after entering a corkscrew
45 Lightbulb in bell-jar from CNZ 2 (near the button which turns the lights off)
46 Fans which make the player hover from CNZ
47 Rotating barrels from CNZ
48 Vacuum tubes from CNZ
49 Rotating wheel from CNZ
4A Bumper
4B Triangular springs from CNZ which knock the player forward
4C Corkscrew from CNZ
4D Pole from CNZ on which you go round and round diagonally upwards or downwards
4E Rotating vertical mesh from CNZ
4F Mud from MGZ and ALZ and quicksand from DPZ
50 Pole from MGZ, at the base of some loops, on which you go round and round
51 Floating platform
52 Smashing pillar from MGZ, smashing spikes from LBZ (repeated entry)
53 Platforms from MGZ which rotate around a centre
54 Air-bubble emitting object
55 Arrow-shooting head from MGZ which you have to hit thrice
56 Moving rotating platform from MGZ with spikes on the sides
57 Platform in MGZ triggered by the rotating blue wheel
58 Swinging spiked ball from MGZ
59 Blue rotating wheel from MGZ which is triggered by a Spin Dash
5A Pulley from MGZ
5B Blue spinning top platform from MGZ
5C Launcher for the blue spinning top from MGZ
5D Triangular springs from CGZ
5E Platform from CGZ with blades at the bottom
5F Retracting spring from 2P mode
60 Elephant block from BPZ
61 Balloon from BPZ
62 Dissolving sand bar from DPZ
63 Button from DPZ
64 Bubble containing item in 2P mode
65 Goal marker in 2P mode
66 Dripper from EMZ
67 Silver blocks from HCZ 2 which move around and expand and collapse into each other
68 Spinning blue column from HCZ
69 Curved twisting blue pipe from HCZ 2
6A Invisible horizontal block which hurts player
6B Invisible vertical block which hurts player
6C Bridge which sags when you walk across it
6D Special water splash from HCZ, where a waterfall hits an object
6E Water drops from HCZ
6F-7F Ring (unused slot)
80 First appearance of the AIZ 1 miniboss, in which he sets the level on fire
81 Bloominator
82 Rhinobot
83 Monkey Dude
84 ??
85 Miniboss from LBZ 1
86 Laser columns boss from LBZ 2
87 Snale Blaster
88 Ribot
89 Orbinaut
8A Corkey
8B Flybot767
8C Black ball machine boss from LBZ 2
8D Boss from CNZ 2
8E Miniboss from CNZ 1
8F-98 ??
99 Jawz
9A Blastoid (HCZ)
9B Buggernaut
9C Turbo Spiker
9D Mega Chopper
9E Pointdexter
9F Caterkiller Jr.
A0 Clamer
A1 Blastoid (CNZ)
A2 Batbot
A3 Bubbles (MGZ badnik)
A4 Driller from MGZ 1
A5 Spiker (MGZ badnik)
A6 Mantis
A7 Blaster (FBZ badnik) prototype
A8 Technosqueek
A9 Boss from AIZ 2
AA Penguinator
AB Star Pointer (ICZ badnik)
AC ??
AD Miniboss from HCZ 1
AE Eggman from LBZ 1
AF Drilling Eggman from MGZ 2
B0 Boss from MGZ 2
B1 Knuckles' boss from MGZ 2
B2 Boss from ICZ 2
B3 Miniboss from ICZ 1
B4 Boss from FBZ 2
B5 Boss from HCZ 2
B6 ??
B7 Egg Mobile which transports Sonic to the final boss arena in LBZ 2
B8 Crushing column from ICZ
B9 Platform from ICZ
BA Breakable wall from ICZ
BB Freezer from ICZ
BC Segmented column from ICZ
BD Swinging platform from ICZ
BE Stalactite from ICZ
BF Ice cube which covers monitors and switches from ICZ
C0 Ice spikes from ICZ
C1 Harmful ice pieces from ICZ
C2 Snowpile from ICZ
C3 Trampoline from ICZ
C4 Miniboss from MGZ 1
C5 Hidden monitors which bounce out when the starpost touches them
C6 Egg capsule
C7 All appearences of Knuckles as a bad guy or as a non-controllable character
C8 Right trampoline support from ICZ
C9 Buttons used by Knuckles
CA Sonic during the AIZ intro sequence
CB Giant ring
CC Miniboss box from LBZ 1. Triggered only in case the player dies during the fight and restarts at the near starpost
CD Lost Eggman object
CE Gumball level from gumball bonus stage. Also initializes all other sprites
CF Springs on the sides of the gumball bonus stage
D0 Squeeze Tag boss from LBZ 2
D1 Special breakable floor from CNZ 2 which causes a water level rise when broken
D2 Button which switches the lights on again in CNZ 2
D3 Towers supporting the Death Egg at the time of launch
D4-FF (unused, crashes game)
Sonic Community Hacking Guide
General
Sonic Music Hacking Guide | SonED2 Manual
Game-Specific
Sonic the Hedgehog (16-bit) | Sonic the Hedgehog (8-bit) | Sonic Eraser | Sonic CD (prototype 510) | Sonic CD | Sonic CD (PC) | Sonic 2 (Nick Arcade prototype) | Sonic 2 (Simon Wai prototype) | Sonic 2 (16-bit) | Sonic 2 (8-bit) | Sonic 2 & Knuckles | Dr. Robotnik's Mean Bean Machine | Sonic Triple Trouble | Sonic 3 | Sonic & Knuckles | Sonic 3 & Knuckles | Sonic & Knuckles Collection | Sonic Crackers | Sonic 3D: Flickies' Island | Chaotix | Sonic R PC | Sonic Jam 6 | Sonic Advance | Sonic Advance 2 | Sonic Advance 3 | Sonic Battle | Sonic Adventure | Sonic Adventure DX: Director's Cut | Sonic Adventure DX: PC | Sonic Adventure (2010) | Sonic Adventure 2 | Sonic Adventure 2: Battle | Sonic Adventure 2 (PC) | Sonic Heroes | Shadow the Hedgehog | Sonic Riders | Sonic the Hedgehog (2006) | Sonic & Sega All-Stars Racing | Sonic Unleashed (Xbox 360/PS3) | Sonic Generations
Legacy Guides
The Nemesis Hacking Guides The Esrael Hacking Guides
ROM: Sonic 1 | Sonic 2 | Sonic 2 Beta | Sonic 3

Savestate: Sonic 1 | Sonic 2 Beta/Final | Sonic 3

Sonic 1 (English / Portuguese) | Sonic 2 Beta (English / Portuguese) | Sonic 2 and Knuckles (English / Portuguese)
Move to Sega Retro
Number Systems (or scrap) | Assembly Hacking Guide | Subroutine Equivalency List | 68000 Instruction Set | 68000 ASM-to-Hex Code Reference | VDP Documentation | Official Sega 32X Documentation | Official Mega-CD Documentation | Official Sega Mega Drive Documentation