Sega CD / Mega CD
Emulators

     Currently, there are four Sega CD emulators available; the "speed" rating is based on my (outdated...) test system, an AMD K6-2 400MHz running with Windows XP Home edition. I couldn't test Kega yet, that emulator will be added here soon:

# Name Speed Compatibility Gfx accurracy Sound accurracy
1 Gens
v1.52

- homepage -

respectively
(PS)
2 WinAGES
v0.27

- homepage -
3 Xega
v0.10

- homepage -

     You can access my compatibility list here (159 games have been tested):

Sega CD emulator compatibility list
last updated: November 11th 2000

Here you can see my personal games collection.

     You might also want to check out the Lucky7 site which has also a compatibility list, even covering Gens and Xega. However, far less games are tested.

All three emulators require ASPI to be installed which is available here.

This page only features a tutorial which explains what is necessary to configure and setup the WinAGES emulator, as this was the first SegaCD emulator released. However, most of the steps are also necessary for the other two emulators, so you'd better read it anyway. ;-)

Here's a quick summary of the strengths and weaknesses of the emulators:

Gens offers full sound support (chip music as well as CD audio) and is the fastest of the three emulators (even with perfect synch enabled it is faster than AGES). With the latest release 1.30, compatibility and CD access speed has been greatly improved and easily tops AGES now. Japanese games now also work; there is no reason you shouldn't prefer Gens over AGES. Gens also has ISO+MP3 support.

WinAGES is a little less compatible and far slower than Gens. Also, the sound support is still in early stages. Japanese games are only supported through using a special trick (see tutorial below)has the best CD support and hence the highest compatibility rate - most of the FMV games work. The scaling/rotating and graphics conversion support is very advanced as well - only very few games show severe graphics problems. ISO images are also supported.

Xega is faster than WinAGES, slower than Gens and has the worst CD support of the triplet - only very few games work directly from CD. The CD access is faster than Gens, though. ISO support on the other hand works very well. You should definitely give it a try if a game doesn't work in WinAGES or Gens. No support for Japanese games.
 

Other emulator projects in the works

 
     Emulating the Sega CD is rather difficult, compared to other console systems. A Sega CD emulator has to include a perfectly working Genesis emulator, so this is the first task to be solved. After that, the complete Sega CD hardware (CPU, graphics processor, sound processor) has to be emulated, and most difficult: the synchronization between the two emulator components. According to a rough estimation of Steve Snake, a Sega CD emulator would run at only one third of the original speed on a Pentium 200MMX.

     In addition to the three projects mentioned above, other emulator projects are currently in the works:
 

Project name Description Version

retroDrive

Tim Meekins has announced he'll be working on Sega CD emulation in autumn 2000.

-

ARES

Joseph Fenton´s ARES site. He currently develops a Genesis/32X/Sega CD emulator for PowerPC/AmigaPPC, but it might be ported to ix86-Linux or even DOS someday.

-

SegaEmu

Atani's project is another valid attempt at emulating the Sega CD, and currently he is making very good progress... We may even see a partially working version of the emulator in June 2000...

-

Discontinued projects: 
EmX project - Hybrid´s Sega CD project - Shro0mz CD project - Next Level project
CDX 1 project - Synergy - NinjaEmu - VGen - Sega CD Exile

     As soon as any of the projects sees its first public release, you will be able to read everything about it on this site, so don't forget to bookmark it! :-)

     By the way... Did you know that the Sega CD is the console system which saw the most emulator hoaxes? Since I monitor the emulation scene (1996), I have seen at least five "emulator" releases with the sole purpose to bring some fame to the "authors", but none of them didn't even have a working Genesis emulation.

     The most recent hoax was the "Millenium" project. As soon as I find some time, I will post some excerpts from the Tavern where my friends and I decloaked the project and revealed it as a hoax. It is a funny read and should serve as a warning to everyone who is creating another hoax - noone has escaped the proving eyes of Flavio, the Scribe, Steve Snake and me yet! Once upon a time, I created a movie which shows how easy a fake emu can be made... I'll upload that, too. 
 

WinAGES Borg: A tutorial

 
Introduction & History

     On October 15th 2000, Jeffrey Quinn released version 0.22a (aka "Borg") of his emulator WinAGES. As it is the first emulator which allows you to play Sega CD games, it is a milestone in the history of Sega emulation. More than four years lie between the release of the first Genesis emulator (GenEm in 1996) and the release of WinAGES Borg - a nice proof of the fact that it is very difficult to emulate this system.
     The current version (
0.25a) is more compatible than the initial release, and most of all a lot faster (though still rather slow, especially on non-Intel CPUs).
     If you are interested in the history of the Sega CD console, I suggest you check out
Sam Pettus' background report called "A Console Too Soon", which can be found at SegaBase (see link on the right navigation bar).

What does WinAGES Borg emulate?

     The Sega CD not only adds a CD drive to the Genesis, it also improves it with another CPU, a graphics chip for scaling&rotating images and a PCM sound chip. The current version of WinAGES emulates the graphics chip partially (not all effects are emulated correctly), but does not emulate the sound chip. However, CD audio tracks are played. Many games which use one of those components extensively (for example Thunderstrike, Soul Star, Lunar 2...) do not work yet. The "basic" system design (inter-CPU communication, CD drive) is emulated however. Jeff did not use HLE (High-Level Emulation) for the BIOS - he managed to emulate the CDC/CDD (low level CD drive access functions) directly, which means that overall emulation will be a lot more compatible in future revisions of the emulator.
     "In future revisions?", you ask. As a matter of fact, only a few games are actually playable with the current version of the emulator (see compatibility list below, still referring to 0.24a though). Many games show something, e.g. the intro, some full-motion videos... But most of them crash at a certain point because they use some yet unemulated features of the Sega CD system.

Necessary files

If you want to play Sega CD games using WinAGES, you need the following files:

  • The emulator itself: WinAGES 0.25a archive
     
  • ASPI. This is a special interface for accessing the PC's CD drive. It is available here. Your system needs to be restarted after installing it.
     
  • The Sega CD BIOS files. They are available here
     
  • The Genesis OS ROM, available here
     
  • The 32X BIOS files, available here
     
  • And of course: Sega CD games. WinAGES supports the direct use of your PC's CD/DVD-ROM drives to play "real" Sega CDs as well as the use of ISO images. I do not know any sites currently carrying ISO images. DO NOT ASK ME, and DO NOT ASK FOR IT IN THE TAVERN.

Getting started

     After you have downloaded all the necessary files above, unpack everything into a newly created directory. Then start AGES.EXE. The first thing you need to do is to specify all the System ROMs. Select "Config" - "File IO" - "Load System ROM". If you have downloaded all files from the above links, the file mapping for the system ROMs is as follows:

  • Genesis = Genesis_OS_ROM.bin
  • 32X Master SH2 = 32X_M_BIOS.BIN
  • 32X Slave SH2 = 32X_S_BIOS.BIN
  • 32X M68000 = 32X_G_BIOS.BIN
  • Sega CD (U) = scd_110.bin
  • Sega CD (J) = mcd_101.bin (not emulated yet, however!)
  • Sega CD (E) = mcd2_200.bin

     Set "Config" - "Machine" - "Miscellaneous" - "Region" to Auto Detect. Activate Use System ROMs for "Config" - "Machine" - "Genesis" and "Config" - "Machine" - "32X". Adjust the "Frame Skip" and "Screen Size" settings in "Config" - "Graphics" according to your PC's speed. If you intend to play "real" Sega CD games through the use of your PC's CD/DVD-ROM drive, you need to select the Default CD Drive in the "Config" - "File IO" menu.
     Now, WinAGES is set up to play Genesis, 32X and Sega CD games.

Playing the games

     You can either play a game directly from CD, or you can play it from an ISO image. To do the first, simply insert the Sega CD game CD into your default CD drive and start AGES. All you need to do now is to select "File" - "Boot Sega CD". If you want to play from an ISO image, select "File" - "Load ROM" (don't forget to set the file type to Sega CD) and specify the ISO image. Please not that many games do not work in ISO format because they require the CD audio tracks.
     Depending on the game's country, the well-known American or European startup screen is shown - press start, and the game starts loading. Please note that Japanese games can only be played using the following trick:
When the Japanese BIOS title screen is display, press the Start button repeatedly very fast. That way, a part of the BIOS code is skipped and the game might load.

Final words

     As I pointed out several times, the release of WinAGES Borg is a milestone for the Sega emulation scene. Jeffrey Quinn has achieved something which has thought to be almost impossible, because of the general complexity of the system and especially because of the lack of technical documentation available for the system. The release of WinAGES was a complete surprise. Kudos to him for that!
     On the other hand, WinAGES is far from being perfect in terms of Sega CD emulation. Let me summarize its drawbacks: In its current state, only very few games are playable, it has no sound support except CD audio. 
    But WinAGES has a lot of potential, as shown with the latest release (0.25a), and I am certain that Jeff will do everything to enhance it in the areas I mentioned. He has clearly shown that Sega CD emulation is possible, and that usually means (quoting him): "Let the competition begin!". Two other emulators have joined this competition now already, and I'm pretty much certain that we will see some other working Sega CD emulators as well.

     For now, I wish everyone a lot of fun with WinAGES Borg. When you've finished playing around with it, please join the Sega discussions in the Tavern, to give the authors some feedback.

 
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