Towards the end of the life of the SNES, developers were coming up against problems. They had squeezed almost every drop out of the hardware, and the games that they wanted to make simply couldn't be done.

Or could they?

Capcom had recently made Street Fighter Alpha 2. Tri-Ace had plans for Star Ocean. Hudson Soft had Far East of Eden Zero in the pipeline. Unfortunately, they looked at their graphics, and then at the SNES cartridge, and then back at the graphics, and then they sighed. For it could not be done. Everyone said it could not be done.

But they said that the Saturn wouldn't handle Quake. They said that we'd never get to the moon. And they said that the earth was flat, so quite frankly, don't listen to them.

Some clever guy at Nintendo figured out a incredible compression routine, which could fit 140 Mb of graphics onto a 40Mb cartridge, (so I hear) along with sound, coding, etc. This technology was named SPC7110 - I will leave that node for someone with technical knowledge, as I have no idea how it works.

Star Ocean from Tri-Ace and Street Fighter Alpha 2 from Capcom also needed compression, but these games used a different compression technique, called SDD1. I must confess I am not entirely sure what the difference is between the two, but I think (from checking the size of my graphics folders) that SPC7110 has a more advanced routine than SDD1 because the folder with my FEOEZ graphics in is 17 Megabytes, while the other two games have folder only about 5 Megs in size.

The problem for people like me, who play SNES games thanks to the gift of emulation, is that as yet, no one has a clue how this compression routine works. Which means that emulators cannot be coded to decompress the data from a rom. Which means that if you try to play a Star Ocean ROM on Zsnes, all you will get are some dodgy shapes floating around, with the music playing in the background. This had people stumped for a while.

But of course, it is possible to emulate these games, even if it is cheating (technically). One day maybe the compression will be figured out, but until then, we can enjoy these games with graphics packs. These are essentially a bunch of files which have been dumped off the rom after the Snes has decompressed them. You simply keep them in a place where your emulator (as far as I know only Zsnes and Snes9x support graphics packs) knows about them, and then the emulator looks at these packs of uncompressed files for the graphics, instead of the graphics on the rom which are unreadable.

Unfortunately, Graphics Packs tned to be hard to get working, especially for newbies who don't have a clue what they are doing. I will attempt to provide a guide to setting up you folders and files for the 4 games that use graphics packs. There are also a few more games which need graphics decompression before they will be playable (such as Top Gear 3000 and Dungeon Master) but as yet they do not have graphics packs, that I am aware of anyway. If you know otherwise, let me know, and tell me where to get the packs.

Star Ocean

  1. You'll need a good version of the Star Ocean rom, and the graphics pack, which is available from the site for Dejap (see below).
  2. Put the rom (in it's unzipped form) in a folder along with all the files from the graphics pack .zip file.
  3. Run the DeXor.exe file which came with the pack.
  4. Type the Star Ocean rom's filename into the Dos box generated by DeXor.
  5. A directory named SOCNSDD1 will have been created - move this to your emulator's Save files folder (if you have set one). If not, move it to the directory you store all your roms, (it should have lots of .zst and .srm files in it).
  6. Take the file SDD1GFX.IDX (included in the graphics pack) and put it in the SOCNSDD1 folder.
  7. Play the rom in Zsnes 1.30b or later - it won't work in any other emulators.
  8. It should work. Hopefully.

Street Fighter Alpha 2

This one is much easier:

  1. Get the US version of the SFA2 rom.
  2. Get the graphics pack from Dejap Translations - it's in a news item about half way down the main page.
  3. Create a folder called SFA2SDD1 in your save files folder, or if you don't have one, in the folder where you keep your roms.
  4. Unzip all the files (except the readme) from the graphics pack into this folder.
  5. Run the rom (I presume it will also need Zsnes 1.30b or later, but the latest version is 1.36; get that and you should be fine.

Far East of Eden Zero

This one is the tough one.

  1. Get a good version of the rom.
  2. Download the graphics packs (all 9 of them) and the DeXor .zip file from Dejap Translations.
  3. Unzip all the graphics files into a folder.
  4. Put the rom in this folder as well.
  5. Put the DeXor program (from the zip file) into this folder.
  6. Start up a Dos window and navigate through your folders until you are in the one with all the graphics files etc.
  7. Run "DeXor.exe <Name of FEOEZ Rom here>"
  8. A folder called FEOEZSP7 should have been created (probably in the root of whichever drive you are using). Move it to either your save files folder or your rom folder.
  9. Make sure the INDEX.BIN file is in that directory.
  10. Put your FEOEZ rom in you normal rom directory.
  11. Run the game with Zsnes 1.30b or later.
  12. As the game first loads, you will be asked to press A and then wait a while. It will run tests and then ask that you power off the system - simply reset your emulator.
  13. You will now be asked to press B, and then wait for some secondary tests to be done. When this is over, you should reset again.
  14. Now when you play the game it should work fine, and you will never need to perform the check again, unless you delete the <romname>.SRM file in your save folder.
That one is the hardest to get working, so keep trying. If totally stuck, the Dejap forums will have some threads which offer help.

I hope this helps you enjoy the games as much as I do. Beware: Star Ocean and FEOEZ are still in Japanese - translation by Dejap is in progress, but not yet done for either. SFA2 should be in English, if you have used the right rom. If I can find enough out about the mysterious "Momotarou Happy Train" or whatever it's called, I'll add instructions, but I don't think anyone has bothered to decrypt the graphics yet.

UPDATE! I have managed to track down this mysterious ROM, and it appears to be properly called Momotarou Dentetsu Happy, according to Gamefaqs. I can confirm that it is an SPC7110 based game (when you load a rom in Zsnes a display will tell you if it is a special type.), and because it has the same button press/test/reset sequence at the beginning. Information apart from this is scarce though - at GameFAQs there is an entry for the game, but no reviews, FAQs, Walkthroughs, or codes of any sort. There is a message board for the game, but there are no posts on it. I'll let you know if anything interesting turns up, or if I find the graphics for it.

UPDATE! I have acquired the graphics pack for the game (they are quite rare, and were only dumped recently) and (finally)got it to work. The game appears to be a sort of take it in turns party game (a la the Mario Party series where the players drive trains around a city. There is an absolute ton of Japanese menus to go through before you can start a game, making this a very difficult game to fathom your way through, but I'm sure Japanese speakers will enjoy it. The graphics are very colourful, and very stylised. There is as of yet no translation effort that I know of, so we will have to wait. Anyway, the method to get it to work is....

Momotarou Dentetsu Happy/Momotarou Happy Train

  1. You'll need the rom and Snes9x, the other big snes emulator. Zsnes does not currently support this game, as it locks up on the developer (Hudson) screen, even if you have the graphics pack.
  2. You can download the graphics packs (there are 4 of them) from a number of mirrors, which are linked from
  3. Once you have all the packs, unzip them into one folder called SMHT-SP7 (note the hyphon). This should be placed in the folder with your roms, or in your Snes9x freeze file directory.
  4. Play the rom in Snes9x version 1.39mk3b (available at the graphics pack mirror sites).

If the situation changes and Zsnes becomes compatible with the game (something which I suspect will be in a future release of Zsnes) then I will update this node. I have also heard about another SP7110 game, but I have no information on it, so I will not post anything about it. I will endeavour to find out some more, and update this node again.

Oh no not more UPDATEs! Thanks to a team led by Andreas Naive and also containing The Dumper and Neviksti, the SDD-1 compression and decompression algorithm has been cracked. This means that code has been released which can be incorporated into any emulator to allow Star Ocean and Street Fighter Alpha 2 to be played with no graphics packs. I'll leave the instructions here all the same, because not only did I spend ages writing this, it should be known that for people with slow computers, it is highly recommended to keep using graphics packs, because it is quite a processor intensive algorithm used to decode the data on the fly. This means that even when SDD-1 code gets incorporated (I hear that Matthew Kendora of Snes9x has it pretty much done, and just wants to tweak it before releasing, and that the newest Zsnes WIP has support) a decent number of people won't want to use it.

It should also be made clear that this is SDD-1 code only. SPC7110 games (FeoeZ, Momotaro dentetsu Happy, and a few others which don't yet have widely available packs) will still need packs, and will do for the forseeable future, as SDD-1 took a hell of a long time to crack. This means that people may be reluctant to work on this other chip.

Thanks to RPGeek for prompting me to mention this new development.

Playing ROMs (which worked) of the following games:

Tomato's Website -
Packs available for download from Dejap's site:
Instruction files included with the Graphics packs.

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