Sonic Classics

From Sonic Retro

Not to be confused with the website Sonic Classic or the fangame Sonic the Hedgehog Classic.


SonicClassics title.png
Sonic Classics
System(s): Sega Mega Drive
Publisher: Sega (US, Europe), Tec Toy (BR), HiCom (KR)
Game total: 3
Genre: Compilation
Number of players: 1-2
Release Date RRP Code Rating
Sega Mega Drive
1997-04-24[1] $? 1190
ESRB: Kids to Adults
Sega Mega Drive
1995-08[2] €? 1190-50
Sega Mega Drive
1995-08[2] £? 39.99[2]
Sega Mega Drive
199x $? FSON16SMC
Sega Mega Drive
(3 in 1)
199x $? ?
Sega Mega Drive
1997-06 R$? 042780
Tectoy: Todas as Idades
Sega Mega Drive
1997 ₩? ?
Sega Mega Drive
199x  ? MDJ1190
Sega Mega Drive
199x  ? ?

Sonic Classics, known as Sonic Compilation in Europe, is a compilation of three games for the Sega Mega Drive stored on a single cartridge: Sonic the Hedgehog, Sonic the Hedgehog 2, and Dr. Robotnik's Mean Bean Machine. Sonic Classics was included as a pack-in title with some editions of the Mega Drive hardware in Europe. The game was not released in Japan.

The three games appear in almost exactly the same form as in their original release, with the exception of some revisions to their code (see their individual sections below). The only new content is a game selection menu, controlled by using the Left and Right directions on the D-pad and new sprite renderings of the box art for each of the three games. Once a game is selected, players are not able to go back to the menu unless the console is reset or turned off and on again.

This game is one of two that, when "locked on" with Sonic & Knuckles, will enable players to play the entire Blue Sphere game, instead of just one level. The other game that enables this is the standalone version of Sonic the Hedgehog. This is because when locked-on to a ROM larger than 2MB, Sonic & Knuckles maps the last 2MB of the locked-on ROM rather than the first 2MB, and Sonic Classics happens (or was designed?) to put Sonic the Hedgehog at the 2MB mark. This is a quirk in the Sonic & Knuckles cartridge's mapper, which is not reproduced in emulators.

The background music and chime heard when a game is selected in the menu are from Dr. Robotnik's Mean Bean Machine itself.


Sonic the Hedgehog

This version of the original game is the same as the standard worldwide REV00 release, except for a new bug in Scrap Brain Zone involving the cycling palette. The bug is caused by the fact that the pointers for palette data are only two bytes long. In Sonic 1 alone, this isn't a problem because palette data lies within the first 0xFFFF of the ROM. However, in Sonic Classics, the data comes after 0x10000, so part of the address is truncated in the pointer, causing incorrect data to be loaded.

Sonic the Hedgehog 2

It was conjectured for some time that the version of Sonic 2 included in Sonic Classics was the former game's REV02, i.e. a second update to its code that had been officially (if silently) made by Sega themselves. This was shown conclusively in June of 2012 when Esrael, who was now using this version as the code-base for his famed hack Sonic 2 Delta, released a ROM of the game extracted to work on its own and followed this shortly thereafter with his disassembly of said ROM[3], which demonstrated that Sega had implemented various bug-fixes and other alterations to the code in time for Sonic Classics.


There are several issues with the version of Sonic 2 included in this compilation. Contrary to popular belief, these bugs are specific to Sonic Classics, and are not present in any other known instance of REV02 (Sonic 2 for Mega Play, Knuckles in Sonic 2, Sonic Jam).

These bugs are seemingly caused by corrupted constants in the game's source code, with all of them relating to nonsensical bitmasks.

  • The sparks that Mecha Sonic leaves when he slides are erroneously not mirrored when he turns around.
  • The above issue also affects Grabber's legs.
  • Sonic/Tails is no longer able to Spin Dash off the Tornado in Sky Chase Zone, and instead briefly hovers in the air.
  • In Wing Fortress Zone, the vertical conveyor belt platforms no longer cause Sonic/Tails to fall when they retract into the wall while they're stood on it. This causes them to be able to walk on the air.

The original cheat codes contained on the cartridge still work here, but the game enhancer codes do not.

Hidden content

Sonic Retro emblem.svg Main article: Sonic Classics/Hidden content


Sonic Retro emblem.svg Main article: Sonic Classics/Manuals

Physical scans

Mega Drive, US
Sonic Classics 3-in-1 (BS).jpg
Mega Drive, EU
Mega Drive, UK
SonicComp MD UK cover.jpg
Mega Drive, PT
SonicComp MD PT cover.jpg
Mega Drive, PT (alt)
SonicComp MD PT alt cover.jpg
Mega Drive, GR (Zegetron)

Mega Drive, AU
SonicCompilation MD AU Box.jpg
Mega Drive, AU (3 in 1)
SonicClassics MD AU 3in1 cover.jpg
SonicCompilation MD AU Carttop.jpg
SonicCompilation MD AU Cart.jpg
Mega Drive, BR
Classics md br cover.jpg
Mega Drive, KR
Sonic Classics 3-in-1 (Korea).jpg
Mega Drive, NZ

Mega Drive, ZA

Technical information

ROM dump status

System Hash Size Build Date Source Comments
Sega Mega Drive
CRC32 8c70b84e
MD5 1e8c38878d4184977718b8b3c90642b8
SHA-1 109e6d7b31d00fbdb9d4ecb304d4ea19e96c8607
3MB 1995-06 Cartridge (EU) REV00
Sega Mega Drive
CRC32 95b5e8d7
MD5 59a5029e58a43c40b715fb8906e6634f
SHA-1 2196cbe754cfcd1d7bbbd0a8a45ae44de4deb2fb
3MB 1997-01 Cartridge (US/EU) REV01


Sonic Classics
SonicClassics title.png

Main page


Hidden content
Region coding

Sonic the Hedgehog games for the following systems
Sega Mega Drive

Sega Mega-CD
Sega 32X
 1991  Sonic the Hedgehog | Sonic Eraser     1992  Sonic the Hedgehog 2     1993  Sonic the Hedgehog CD | Dr. Robotnik's Mean Bean Machine | Sonic Spinball     1994  Sonic the Hedgehog 3 | Sonic & Knuckles     1995  Chaotix | Sonic Classics     1996  Sonic 3D: Flickies' Island