Sonic & Knuckles Collection/Technical information

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This is the Sonic Community Hacking Guide for Sonic & Knuckles Collection, the PC version of Sonic the Hedgehog 3 & Knuckles.
All data except for music is identical to the Genesis version but byteswapped (order goes 1,0,3,2 instead of 0,1,2,3).

Level Data

Level Layout

Main Article: SCHG:Sonic the Hedgehog 3 & Knuckles/Level Editing#Level Layout
Location Level
259F34 Angel Island Zone Act 1
25A780 Angel Island Zone Act 2


Art Tiles

These use the standard Genesis format and can be edited with any tile editor.

Start Address End Address Description
1302B 1374A HUD Numbers, Debug Numbers
593DC 70A7B Tails
70A7C 73B3B Mini Sonic
73B3C 76E5B Mini Tails
76E5C 7A2DB Mini Knuckles
7A46C 7D28B Sonic Surfing (Unused)
7E180 84A3F Invincibility Stars, Puff of Smoke, Shields
95118 95AD7 CNZ Cannon
95AD8 96257 Drowning Countdown
96258 96757 SONIC/MILES BG
E7654 E7CB3 Some Knuckles Sprites
E91F4 EAD93 Butterdroid and Cluckoid
EC4D8 ECD43 Some Knuckles Sprites?
EE198 EF838 Hyudoro
F50F0 F776F Knuckles from HPZ cutscene
100F78 101AB7 Knuckles from SSZ
117244 117CE3 Rhinobot
11D5DC 11DFFB Bubbles
11EE54 11FF93 Clamer
1240A8 125087 Penguinator
127E28 129147 Flybot767
1313DC 1320DB Signpost
132D40 137C1F more Knuckles
137CF4 13A993 Big Ring
1A2EAC 1C2DCB Sonic
1C2F8C 1E2D0B Knuckles
1E2F0C 1E6BAB Sonic Extra
1E6BAC 1E94CB Tails Extra

RAM Editing

Main Article: SCHG:Sonic the Hedgehog 3 & Knuckles/RAM Editing

The RAM starts at 08FF0000.

Save File

Offset Type Description
180 $54 bytes Sonic the Hedgehog 3 & Knuckles save slots (8 slots, $A bytes each)
Offset Value Description
$00-$01 Word Slot State
$8000 New Game
$0000 Game in Progress
$0100 Game Complete
$0200 Game Complete with all Chaos Emeralds
$0300 Game Complete with all Super Emeralds
$02 Byte Current Character
$00 Sonic And Tails
$10 Sonic
$20 Tails
$30 Knuckles
$03 Byte Current Level
$0C Last level for knuckles
$0D Last level for Sonic without chaos/super emeralds, or Tails
$0E Last level for Sonic with at least all Chaos Emeralds
$04 Byte Unknown
$05 Byte Something with Special Stages Array
$06 Byte Something with Collecting a Chaos Emerald
$07 Byte Something with Collecting a Super Emerald
$08 Byte Current Number of lives
$09 Byte Current Number of Continues
  • Note that byte $02 also keeps a record of special stages played through, whether you won or lost it. It updates by $01's.
Sonic Community Hacking Guide
SonED2 Manual | Subroutine Equivalency List
Sonic the Hedgehog (16-bit) | Sonic the Hedgehog (8-bit) | Sonic CD (prototype 510) | Sonic CD | Sonic CD (PC) | Sonic CD (2011) | Sonic 2 (Simon Wai prototype) | Sonic 2 (16-bit) | Sonic 2 (Master System) | Sonic 3 | Sonic 3 & Knuckles | Chaotix | Sonic Jam 6 | 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 | Sonic Riders | Sonic the Hedgehog (2006) | Sonic & Sega All-Stars Racing | Sonic Unleashed (Xbox 360/PS3) | Sonic Colours | Sonic Generations | Sonic Forces
Technical information
Sonic Eraser | Sonic CD (prototype; 1992-12-04) | Sonic 2 (Nick Arcade prototype) | Dr. Robotnik's Mean Bean Machine | Sonic Triple Trouble | Tails Adventures | Sonic & Knuckles Collection | Sonic Crackers | Sonic 3D: Flickies' Island | Sonic R | Sonic Advance | Sonic Advance 3 | Sonic Battle | Sonic Shuffle | Shadow the Hedgehog | Sonic Rush | Sonic Lost World
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 | 68000 Instruction Set | 68000 ASM-to-Hex Code Reference | SMPS Music Hacking Guide | Mega Drive technical information