It’s been an eventful couple of months, so there are several things I’d like to talk about today.
New version of the SA1 analog fix
You may have heard of the analog deadzone fix for SA2 DC by OnVar. I was looking at input code in SA1 and found many similarities, so I made a request to woofmute, who successfully ported OnVar’s fix to SA1. The fix is available for the US version (1.005) and the Autodemo. I’m not sure whether the issue is addressed completely or if the fix has any side effects, but it appears to work and it’s definitely better than my old hack, so I suggest you give it a try.
The fix injects custom code into 1ST_READ.BIN. The patched bytes for the US version are as follows. With some patience you could turn it into a very long CodeBreaker code…
;Input function hijack
411e2=0ce0f6f3f5f34c8925c708f235f2488908a10ce0
;Input Patch block 1
41284=20e0f6f304c708f2f5f3b28935f2b08920e0b6aff7ff
;Input Patch Orig code reposition
41406=f7ff20e0f4aef6f3
;float for block 1
4129c=000040c5
There are two ways to get the patch:
If you have the TOSEC GDI of SA1 US 1.005, you can apply an xdelta patch to track03.bin. It works the same way as the SA2 patch in the description of the video linked at the top of this post, so you can use the video for reference.
To apply this fix and more, you can use the new Dreamcast Image Builder that I will talk about in the next section. The Autodemo version of the fix is also available for Dreamcast Image Builder.
Release of Dreamcast Image Builder
This is an update to SA1-DC-HD, a project that originally started as a helper tool to add various enhancements to SA1 DC for playing on the flycast emulator. The project has grown to become a universal patcher for Dreamcast games.
As you can see, it’s heavily inspired by the SADX Mod Loader/Mod Manager and uses the same concept of “mods” to add hacks to games. Of course it’s a lot more limited than the actual Mod Loader, but you can do neat things with it. For example, to test its capabilities I made a mod that replaces Deer with Sheep from SA2:
(Chao body parts not implemented yet)
You can check it out here. All mods from SA1-DC-HD are built-in, so you can use it right away. The wiki explains how to use the tool and develop mods for it.
New Autodemo research
You may have seen new videos uploaded by Speeps and woofmute which demonstrate various debug features of the Autodemo and levels that didn’t work before, such as Casinopolis. This was made possible thanks to the research done by Speeps, woofmute and other members of x-hax, as well as previous research by evilhamwizard, ItsEasyActually, supercoolsonic and others.
As you may know, parts of the Autodemo come from different builds of the game that were at different stages of development. When the Autodemo was put together, only the levels that were meant to be shown in the demo were recompiled, and the other levels were left over from older builds (for most of these, textures and lighting files were also missing). We can tell which binaries were recompiled by looking at file dates on the Autodemo GD-ROM:
You can see that there are three “sets” of files sorted by last modified date. The files that don’t boot were compiled against an earlier version of the game’s main binary (1ST_READ.BIN), so the pointers to functions and data in the main binary are all invalid in these files. However, it’s possible to find the functions and data they were meant to point to by comparing the pointers to known functions and data between these files and the files that boot.
Earlier work on this, which demonstrated partially functional Windy Valley and Sky Deck, was posted by evilhamwizard on Sonic Retro. More recently this was picked up by Speeps, who started putting together a list of known broken pointers and their correct counterparts. As the pointer list grew, more levels became functional when known pointers were replaced. To facilitate mass pointer replacement and game testing, I added Autodemo support to my SA1-DC-HD project (now Dreamcast Image Builder). As we were experimenting with the Autodemo, I adjusted the image builder’s mods system to be more flexible and easier to use and converted (together with woofmute) Speeps’ modifications into mods for it. I also repurposed some of my previous work to find missing textures by matching the names in the Autodemo’s texture lists against textures in the final version, the E3 build, the Autodemo Windy Valley mod for the PC version (where missing textures were recreated by its developers) and Dreamcast SDKs (which surprisingly have some early SA1 textures).
As a result of this combined effort, we got the game to show stuff that was never seen before. For example, here’s a preview of the old version of Chao Race restored by Exant:
Or a very early version of the Mystic Ruins:
Or woofmute’s restoration of the debug object placement editor:
Or a super early version of Twinkle Circuit:
Of course, you also have Speeps’ near-complete restorations of Twinkle Park, Lost World and Sky Deck. The biggest restoration so far is the early Windy Valley, the holy grail of the Autodemo for many SA1 fans. It’s based on Speeps’ and evilhamwizard’s pointer fixes and uses textures from the 2018 PC mod by supercoolsonic & ItsEasyActually.
There’s a lot more stuff released and in progress. We now have a public repository with some Autodemo mods, which you can apply with Dreamcast Image Builder to get the restored functionality and content ingame.
Note: Not all of the mods work on hardware at the moment. flycast is recommended.
This is a quick note to let you know that I will no longer provide updates for the HD GUI mod. The repository has been archived. If you are interested in continuing the mod’s development, feel free to unarchive it and/or make a fork of it.
TLDR version: There was a Korean version of SADX PC released back in 2004. I ported the Korean translation to the Mod Loader, so you can now play SADX in Korean if you install this mod. The mod is compatible with Dreamcast Conversion and Dreamcast DLC but incompatible with HD GUI.
Four years ago I got my hands on a somewhat rare version of SADX PC. I was completely unaware of its existence until I accidentally ran into a listing on an auction, so I got it right away. I’ve mentioned it before in a previous post, and today’s mod release brings the occasion to finally talk about it again.
Introduction and game package
This version was released in July 2004 in Korea by a game and toy company called Sonokong. It’s a complete Korean translation of the game with English voices. The game comes in a box with a fully translated manual, which is also in color! It looks a lot better than black-and-white Japanese and US manuals I’ve seen until now. Here are some pictures of the box, the discs and the manual. Please excuse the poor picture quality, maybe someday I’ll get to scanning these properly.
Installation and initial testing
Just like the US version, the game comes on two CDs. The simple CD check is also the same, so you can install and run the game on Windows 10 and above, unlike the Japanese version which no longer works because of SafeDisc. With the Korean version, you can pass the CD check even with the US version’s CD 2.
The autorun and the installer are also fully translated.
I can’t comment on the quality of the localization since I don’t read Korean, but I can say for sure a lot of work was put into it. Unlike French, Spanish and German translations that come with the US and Japanese versions, this one translates not only all textual data, but also all menu textures, the title screen and the main menu background. But the most impressive part is the Korean font used for subtitles and Chao Garden messages. To my knowledge, this is the only official release of SADX that introduces both asset and programming changes to accommodate a language that wasn’t in the original game. It’s also executed in an interesting way, which we will get to a bit later.
As amazing as this version is, it’s still the 2004 PC port of SADX at its core, so the game has terrible graphics with no mipmaps, broken windowed mode at non-4:3 resolutions, poor music quality etc. It’s pretty hard on the eyes, especially in motion.
(From now on, I’ll be using screenshots from the US version with the Mod Loader and the Korean mod)
Korean localization and option menu differences
Korean text replaces Japanese in this version. English text is also available, although the title screen and the main menu background will always use the Korean versions of the textures. The game doesn’t let you pick Japanese voice language, so only English voices can be used. Interestingly enough, Japanese voices are still included with the game: it just doesn’t show the voice language setting in the options menu and overrides the voice language variable with English as soon as a save file is loaded. However, before a save file is loaded the game still plays the “Select a file” voice from the Japanese voices folder. To work around it, the developers replaced that voice with its English counterpart. The rest of the Japanese voices are untouched.
I’m not entirely sure, but I think such elaborate workarounds to make sure no Japanese is heard in the game may have had something to do with Korean laws regarding Japanese media, which were stricter when the game came out.
Funnily enough the texture for the option was still translated, so when you use the mod on the US version with the Mod Loader, you can select Japanese voices as if the option was intended to be there originally (although it says “Korean” instead of “Japanese”). You can also select other languages for text (not sure if you’d really need to if you’re playing this!), which the Korean version doesn’t let you do.
The localization has everything you’d expect, including character tutorials, Mini Game Collection etc.:
Reverse engineering the Korean font
The implementation of the font used in the last two screenshots is intriguing. What caught my attention initially was the large size of the FONTDATA0.BIN file, which is used for Japanese characters in the original version (1.72MB vs 759KB in the original). My first guess was that they either replaced Japanese characters with Korean ones, or added them to the end of the file with the IDs matching the Korean codepage 949.
I started inspecting the file in SADXFontEdit in SA Tools. As expected, this file contains Hangul characters used to display Korean subtitles and Chao texts. However, apart from those, the file also has some characters from other languages, including Greek, Russian, Chinese and Japanese, which amounts to a total of 20609 characters (for comparison, the original file used for Japanese has only 8836, and almost all of those are Kanji, although Cyrillic and some other characters are present as part of the Japanese codepage). On top of that, soon I realized that character IDs stored in the file matched those of the codepage 1200 (UTF-16).
Yes, you read that right. In the Korean version of the game the subtitle font is an actual Unicode font. Although it only supplies specific blocks of the Basic Multilingual Plane, in theory you could add back the other blocks to implement any language included in the plane. Back in 2020 when I first discovered this, I updated SADXFontEdit with some new functionality, including support for the Unicode layout, so when you select the correct codepage you can see the matching character next to its ID.
As we know, the US and JP versions don’t support Unicode, so how does this work? The game’s dialog texts, menu prompts etc. were compiled into the game as strings encoded with the Korean codepage 949, not Unicode. However, when the game processes text data to create a subtitle texture, it parses the characters and assigns them Unicode IDs to be used to pick graphics from the font data you see in the screenshots above.
This was where I ran into an issue I didn’t understand at first. When I first ran the game, it would either display garbage text in place of subtitles, or just crash. That was how I found out that the Korean version required the system locale (language for non-Unicode programs) to be set to Korean for subtitles to render properly.
If the game already knows it’s converting Korean to Unicode, why does it need that? Eventually I found the answer when I was looking at the game’s font related functions in the disassembly that I quickly cobbled together. The Korean version uses the function MultiByteToWideChar to convert “C strings” (in this case Korean strings in the local codepage) to UTF-16 “wide strings”. It’s an interesting solution considering that other versions have a custom function to parse characters and assign font IDs to them.
So why does it fail when the system locale isn’t set to Korean? The developers call the function with the default first argument (0), which takes the current system locale as the source codepage. As a result, Korean text is converted to Unicode as if its original codepage is whatever you have set as the language for non-Unicode programs. If the developers of the Korean version set the first argument of MultiByteToWideChar to 949, the Korean version would display subtitles correctly on any system regardless of the locale. I think a lot of people would’ve never caught this issue because the game was meant to be sold only in Korea. Anyway, we can fix this on the mod’s side.
Implementing code differences
With such changes to the font system, simply replacing FONTDATA0.BIN in a mod wouldn’t make the game support Korean, and a bunch of hacks had to be done first. One thing to do was to introduce calls to MultiByteToWideChar before letting the game parse text data. As I didn’t know the stuff I explained in the previous paragraphs, it took me a while to realize the importance of these calls, and my initial attempt to get the game to display Korean text correctly were unsuccessful. I gave up on the mod for a while, and it was only this month that I gave it another try and figured it out. Another necessary change was in the function that maps character IDs to bitmap data in the font file. There were overrides for … , 「 and 」, but other than that it was pretty straightforward.
I put together a DLL mod that replaces three text-related functions, then I replaced one Japanese hint message in Emerald Coast to test it. The Mod Loader used a hardcoded codepage for strings that are normally in Japanese, so I added global codepage overrides for all languages, which can now be used by other mods.
At first I wasn’t sure how far I could go with this, but when I finally saw the Mod Loader display Korean text, making a Korean mod started looking feasible. I was also driven by the technical challenge and the uniqueness of this version of the game, support for which required several changes to our tools, which I was happy to implement.
Extracting and importing Korean text
Speaking of technical challenges, obviously I had to somehow extract all Korean text from the game and put it into the mod. Finding it all manually was out of the question, which was part of the reason I gave up on the mod last time. However, after my experience with matching assets between different versions of the game, I was tempted by the idea of automatic splitting. Since the game still has English text, it’s possible to scan the EXE to find it, and then work up the structures to get to the start of each item. There were three types of data that had the largest amount of text: cutscene text, Tikal hints and multi-language strings such as character unlock messages, menu prompts etc. I put together a program to make the task easier. Basically it created an INI file for SA Tools’ split tool to extract the text from the Korean EXE. Of course some manual tweaks were required to ensure all addresses were correct, but the program did most of the tedious work. Cutscene text in particular required almost no touch-ups because I made it verify the text in other languages to ensure it’s the same entry in both games.
Building a mod from this data in SA Tools was a challenge. I had to add custom codepage support and fix a few bugs, but mod building in the tools is more stable now and the end result was worth it.
At this point I ran into an issue many retranslation mods had to deal with. There was some text in the game that wasn’t supported by the Mod Loader and/or the SA Tools at the time. It’s still possible to replace such text in a DLL mod, but I wanted all text replacement to be done via the Mod Loader’s INI-based system, so I had to do some work on the tools again. I added support for the following data types, which can now be replaced in mods without code:
Tikal hints that show up after you die on a boss. These are different from the hints you see in stages, and they’re stored in different ways depending on the boss, so I had to improvise a bit to make them rippable in the tools and replaceable in the Mod Loader.
Mission descriptions for Mission Mode.
Mission Mode tutorial text.
Single language strings, such as unlock prompts for Game Gear games or Metal Sonic. I added them to the SA Tools a couple years ago but not to the Mod Loader.
Multi-language strings, such as character unlock messages or “Welcome to Twinkle Circuit!”. Same as above.
Implementing Chao texts
With all that in place, all Korean text in the game was finally transferred. There was one big obstacle remaining: Chao texts. Although it loads the same font data, the Chao text system in SADX uses completely different code from the system used by subtitles and menu prompts, probably because it was copied from SA2B and duct taped with the SADX font system. So I had to do the same thing I did for the subtitles for the Chao text functions. This was probably the most difficult part of the whole mod. The functions involved with SA2B text were all difficult to hook, and even when I managed to replace them correctly I would only get crashes. It took me a long time to get a working decompilation of the functions that convert strings for the SA2B system. I’d like to thank Kell for a decompilation of these functions in the US version, which I used for reference.
Interestingly enough, the Chao system also uses wide strings internally, but all text is stored in the Japanese codepage, or Korean in this case. The game performs conversion from C strings to wide strings just the same, but the Korean version uses MultiByteToWideChar again instead of the simple parsing function used for Japanese in the original version.
After many hours of debugging I finally figured out the error in my decompiled code that was related to finding character data. In the pseudocode I got by decompiling the Korean version, the cell ID of the character data in the font was calculated by adding 0x776A to the character ID, which made it go out of range. The sign had to be flipped to make it subtract 0x8896 instead. After I fixed that, the text started working.
Now the mod was ready for testing. Out of curiosity I tried it with Dreamcast Conversion and realized that the Dreamcast Chao Garden hints were missing. Luckily they were translated in the Korean version, so I added them to SA Tools, made some changes to DC Conversion to make it more compatible with mods that replace them, and reimported the translated hints. I was happy that even the normally unused Dreamcast hints were translated.
The mod is compatible with Dreamcast Conversion, but with a few quirks. Since there are no Dreamcast menu textures in Korean, Dreamcast Conversion’s replacement of some GUI textures will be undone by this mod. This is a quick fix, and I might update it with proper compatibility eventually. There may be bugs in the mod, particularly crashes. Please send me crash dumps if you run into any.
For obvious reasons HD GUI is incompatible. If you’re interested in making HD Korean textures and an HD Korean subtitle font, please let me know.
This is the first translation mod that works by replacing the Japanese font, and the first to modify font-related code. I hope this release attracts more Korean players to SADX modding and helps other translation mods. I also think it’s truly amazing that after all these years of research and reverse engineering there are still new things about this game waiting to be discovered.
The SADX Mod Installer was discontinued back in 2022. However, with the arrival of the new SA Mod manager and retirement of the original SADX Mod Manager I felt it was necessary to update it. Many people are still using it, and Linux/Steam Deck tutorials seem to rely on it. Although I want to retire the installer as soon as possible, I made the following update to make it easier for people using it right now:
If you’re running Windows 7 or above, it will install the new SA Mod Manager (auto picking x86 or x64). If you’re running Windows XP, it will install the legacy SADX Mod Manager.
.NET 7.0 Desktop (x86 or x64) is installed automatically on Windows 7 and above.
The installer was made compatible with Windows XP. All tools, including Steam conversion, are completely functional on XP. Online functionality will not work on XP and 7 due to outdated certificates, but it might work if the system has correct certificates.
The Steam conversion process has been altered to rely on patches. Now the installer doesn’t supply the EXE or DLLs from the 2004 version, instead it patches the Steam version to turn it into the 2004 US version using a 5MB diff file. This was made possible thanks to HDiffPatch. Best Buy, EU original, Sonic PC Collection and Korean versions of SADX are also patchable.
The installer still doesn’t support the new configuration format introduced in the new Mod Manager, and I think it will probably stay that way. However, the new Mod Manager picks up the old format settings generated by the installer so this should be no problem to the players.
At some point in the future the new Mod Manager will handle the Steam conversion, and the installer will no longer be necessary. Some of its features will be implemented in the new Mod Manager or through other means: for example, Guide Mode could be done as a web page with 1-click install links.
Previously you had to use BetterSADX or the SADX Mod Installer to transfer savegames to the 2004 version, but soon it will be possible to load the Steam version’s saved games in the Mod Loader. You will be able to load files directly from their original location, so no transfer is required whatsoever. If you play a Steam saved game in the modded 2004 version, the original Steam version will also be able to load it, so you can play the same file on both versions. The Chao Garden save is also supported: if you load a saved game located in the Steam folder, it will use the Steam version’s garden file. As you can see in the screenshot, custom filenames (ANSI/English only) are also possible, so your saved games no longer have to be named “SonicDX??” for the game to recognize them.
The format used for saved games is almost identical between the two versions, but there are a couple differences that make them incompatible. You can load 2004 saves in the Steam version if you rename them, but not the other way around. The files created by the Steam version are 16 bytes bigger (1408 bytes vs 1392 in the old port), and 12 of these extra bytes are used to store the file creation date and time. At the beginning of the file there is a checksum, and both versions use the same algorithm which calculates the checksum value based on the contents of the whole file. The reason the 2004 version won’t load Steam saved games is because the game only accounts for 1392 bytes when reading the file and calculating the checksum, which doesn’t match because it doesn’t include those extra 16 bytes in the calculation. The Steam version removes the checksum check on the file select screen so it recognizes saved games from the 2004 version, although the date and time might look wrong. When progress is saved in a file that originally came from the Steam version, the Mod Loader writes the current date and time into the file so it should display correctly in the Steam version as well.
Dreamcastify, a website that documents SADX downgrades, was having some technical issues throughout the last two years. Some video comparisons that were hosted on Youtube were taken down, and after a WordPress update the pages didn’t load properly and many images were missing. I reworked all pages so that they load again and made the following changes:
All video comparisons are now hosted on the site itself.
The pages display smaller JPG images by default, and a full-size PNG version of each image can be seen if you click on the preview. This made the site much more responsive.
There were some minor text edits (mostly wording) and some info updates regarding mods and emulation.
The feedback section was removed. Sorry, I don’t have the resources to read all of the comments. I haven’t looked at the newly arrived 850+ comments for about 3 years now, and from a quick glance they seem to be just spam anyway.
This is likely the last update to the site for the observable future. I was originally going to take it down because I didn’t have interest in updating it anymore, but then I thought it should be left online as a source of information, so I took a weekend to sit down and fix it for good, as well as rewrite some things.
I’d like to thank KGL for getting the initial editing and format updates done.
Today I’d like to introduce a project I’ve been meaning to start for a long time. Gamecube Project is an ongoing attempt to research the differences between PC (2004) and Gamecube versions of SADX, and implement them as a mod for the PC version. While this mod will be nowhere near as ambitious and fast-progressing as Dreamcast Conversion, I’d like to release the first version of the mod to get started.
(This mod isn’t compatible with Dreamcast Conversion. You can’t load both mods at the same time).
Although I’ve been contemplating it for a while, there were many technical difficulties in getting this off the ground. Here’s a list of steps we’ve made over the years before this project could exist:
SonicFreak94 developed a mod that makes the lighting in SADX PC more Gamecube-like. I made an experimental fork of this mod with some attempts to improve accuracy.
Exant and hesoyaam figured out REL file compression in the final version of SADX GC, and I integrated it into SA Tools. Edit: It was pointed out to me that this post doesn’t mention that REL compression was figured out by RikuKH3 first. This is indeed true. REL compression was first figured out by RikuKH3, who got a commission to make a tool to decompress REL files for a Russian translation project. Since RikuKH3’s tool was closed source, we needed a better long-term solution for SA Tools. The SACompGC library linked above is based completely on decompiled code from the Gamecube version of SADX. However, the Russian translation mod also included a hacked DOL file that bypassed compression to enable the game to load uncompressed REL files. Exant compared that hacked DOL file with the original to find the relevant code to decompile.
I did some initial research on GCAX soundbank formats used in Gamecube versions of SADX, SA2B, Heroes, Shadow and Billy Hatcher.
I mapped out the data in SADX GC (with contributions by End User) and created a template for SA Tools to be able to extract it.
To make a direct comparison possible, I matched up the data with filenames we got from X360 symbols like I did earlier with the PC and DC versions.
I wrote a comparison tool that lists differences in levels and models and generates C++ code to patch the PC models to match the GC version. This patcher was first used in Dreamcast Conversion, but it was originally developed for Gamecube comparisons.
Exant, Kell and I implemented support for Gamecube GVM files in the Mod Loader.
The last one in particular addressed a major roadblock because I wanted to use original GVM textures rather than texture packs. Thanks to Exant and Kell it is now possible.
Now let’s discuss the actual differences between SADX PC and SADX Gamecube. Unlike the Dreamcast version, there are no major design differences, and most of the changes can be explained by technical factors rather than artistic choices. Some differences are easier to notice while others are more subtle, but I’ll try to cover all of them.
Lighting
The lighting in the Gamecube version often looks pretty different from the PC version. There are several reasons for these differences:
While both versions use the same format of lighting data, the PC version uses that data to set up Direct3D lights, while the Gamecube version uses a custom lighting formula that applies diffuse lighting last, which makes the environments look more vibrant.
For character and object lighting, the Gamecube version generates palettes and applies them per-pixel, while the PC version uses only some of the values to set up Direct3D lights, which look different either way. The Gamecube version uses the ambient value, two colors for diffuse and two colors for specular to generate the palette, while the PC version only uses the ambient color and one specular color.
The PC version uses a high multiplier for specular lighting, which results in an even more “glossy” look than in the Gamecube version, which was already “glossy”. Also, specular lights in the PC version are set up as view-dependent (they move when the camera rotates), while on the Gamecube specular is view-independent (stays in the same place regardless of camera rotation).
The renderer in the PC version ignores built-in vertex colors for object models. A fix for this was introduced in the Mod Loader.
Although the lighting data format is the same, values for several levels in the PC version were edited to make the lights brighter. This washes out the lighting even further and makes areas look almost fullbright. Simply importing lighting values from the Gamecube version into the PC version (as done by the Gamecube Project mod) even without changing the underlying system makes night lighting in the Mystic Ruins much more convincing.
Gamecube
PC
PC with Gamecube values
SonicFreak94 has made a mod that recreates parts of the Gamecube lighting system in the PC version. At the moment character lighting is not accurate and some stages still look a bit different. I’ve made a fork of this mod in an attempt to improve accuracy, and some stages look closer to the Gamecube version, but others are still different. I’ve also tried to use more values to improve character and object lighting, but since it relies on the same same formulas as the old Direct3D lights, it doesn’t look accurate to the Gamecube version. Still, I think the work that went into the mod is important progress towards fully replicating it in the PC version eventually.
GamecubePC originalPC with GC valuesPC with GC values + lighting modPC with GC values + lighting mod (fork)
Some special effects
The PC version has some bugs that prevent certain effects from working properly. The Dreamcast and Gamecube versions had bubbles moving inside Chaos’ body, but in the PC version they are static. This is fixed in Dreamcast Conversion and Gamecube Project.
Material colors
The renderer in the Dreamcast and Gamecube versions ignores material colors in most cases (Chao models use them in the DC version though), while in the PC version it converts material colors to vertex colors. This results in unintended tinting of some models. For example, the clouds in Red Mountain are supposed to be white, but the PC version makes them gray:
Gamecube
PC
I added a fix to the Mod Loader that makes material colors in all models white, so this issue is no longer relevant.
Textures
The PC version uses the same texture format as the Dreamcast original, while the Gamecube version uses a different texture format. Both formats have their strengths and weaknesses, which makes some textures look better on GC, although generally the DC version has the sharpest textures and the PC version has the worst quality textures. Here are some examples featured previously on the Dreamcastify blog:
There are some exceptions though, for example here’s a texture from the character select screen:
Dreamcast
Gamecube
PC
Here you can see that the Gamecube version has severe quality degradation, while Dreamcast and PC look the same.
On the other hand, there are several textures on the Gamecube that are sharper than on the Dreamcast. We could only find a handful of these among thousands, but they do exist:
Unfortunately we can’t pick the best quality version of every texture from all versions because many textures in SADX were edited or replaced. Sometimes it’s a simple color edit, other times it’s based on the same source material but composed differently, and sometimes it’s a completely different texture. Here are some examples:
Top is Dreamcast, bottom is Gamecube
The Gamecube Project mod puts back almost all Gamecube textures in the PC version, so if the PC version has a better quality texture there will be a quality regression. However, most of the time Gamecube textures are higher quality than PC textures.
Another difference with textures is lack of mipmaps in the PC version. Although the Mod Loader now generates mipmaps automatically for textures that don’t have them, the original PC port looked pretty terrible without them:
Textures in the Gamecube version have built-in mipmaps so the environments look much smoother in the distance.
Finally, the PC version introduces mirroring for some textures instead of relying on models’ UVs and material flags, which reduces texture resolution. The Dreamcast and Gamecube versions don’t have this, so their textures are higher quality.
Levels and models
Although they look similar enough to be mistaken as identical, many levels and models in the Gamecube version are different from the PC version as far as their data goes. There are three main reasons for these differences:
Models that use mirrored textures have had their UVs and material flags adjusted in the PC version.
Some levels have a different model order, and sometimes the PC version has extra models in the level. Most of the time this has to do with the addition of the detail (clip) setting in the PC version, which is used to make certain items invisible to improve performance. There are also other adjustments related to transparency sorting, which was possibly different on the Gamecube.
There were some texture ID bugs in the Dreamcast and Gamecube versions which the PC version fixed. For example, E-102 Gamma’s Laser Blaster upgrade in Egg Carrier’s water reservoir room was changed to use correct textures.
While points 2 and 3 are fine to leave as-is, models in the PC version need to be patched to look correct with Gamecube textures. This is one of the things the Gamecube Project mod does.
Menus, fonts and branding
The Gamecube version uses the same subtitle font as the Dreamcast version (though it draws a bit differently), while the PC version switches to a different font:
Top: Dreamcast, middle: Gamecube, Bottom: PC
The Pause menu has a controller configuration section on PC, which the Gamecube version doesn’t have. The quit confirmation prompt only responds to the A button on the Gamecube, while on PC both A and Start buttons can be used.
The Gamecube version has Nintendo copyright text on the title screen and images of the Gamecube controller and buttons in menu screens, while the PC version has keyboard images. The save icon in the Options menu is also different, and the arrows have a bouncing animation on the Gamecube. The Gamecube Project mod restores the save icon animation, controller images and button prompts, as well as the copyright text (at 640×480 only). The fonts will be restored at some point in the future.
Gamecube
PC
Chao
The Gamecube version has GBA connectivity features that are disabled in the PC version (maybe we’ll try to restore that someday?). The model used by the Chao Transporter/Name Machine and its textures were changed in the PC version to remove references to Chao Adventure and GBA-related branding. The PC version also removes the Party Race option in Chao Race, so your Chao can only compete against CPU opponents and not against each other. This is something I’d like to tackle in the Gamecube Project mod and/or Dreamcast Conversion someday.
Sounds, music and voices
The Gamecube version uses ADX music and voices, while the PC version uses WMA music and voices, which are lower quality. This is no longer an issue because the Mod Loader implements ADX support through the BASS library, and you can simply use the ADX Audio mod to get the best quality music and voices.
For sound effects it’s a lot more complicated. The Gamecube version uses a sequenced sound system resembling that of the Dreamcast version. It uses similar data structures and can have DSP effects, although its capabilities are largely unknown at the moment. The PC version doesn’t have anything like that, and uses simple WAV sound effects packed into DAT archives. Although I’ve done some work on getting data out of Gamecube soundbanks, getting them to work in the PC version isn’t feasible at the moment. However, if we figure out enough about the format, we may be able to convert (or record) sequenced effects to regular WAV files and use them in the PC version, like the Sound Overhaul mod does.
Also, the Gamecube version uses Dolby Pro Logic II for 3D audio, while the PC version uses DirectSound3D (the original Dreamcast version used QSound, a binaural 3D effect). While we may not be able to make it identical to either version, 3D sound implemented in the Mod Loader using the BASS audio library is a good alternative.
Fog
The PC version uses Direct3D fog formulas, and all stages are set up to use linear fog. In many areas the fog starts too close to the camera so it washes out details, and the game looks better with fog disabled or adjusted to use longer distances.
The Gamecube version uses different fog modes (linear mode, two exponential modes and two “backwards” exponential modes). The most common fog formulas used by stages in the Gamecube version are linear and “backwards” exponential. Since the exponential formulas are different in Direct3D (and the game uses linear anyway), fog calculation is completely different. In addition, we haven’t checked yet whether fog distances are different between versions (they probably are).
There are several ways to address these differences. The most accurate would be to restore original fog data and use Gamecube fog formulas in the GC lighting mod’s shader. Or, like with Dreamcast Conversion, fog distances in the PC version could be tweaked to look similar.
Water effects
This is perhaps the most visible difference between versions. The Gamecube version has multiple water effects. The distortion is the most obvious effect, but there’s more. Let’s have a look at all of them.
First, the distortion of the whole screen when the camera goes underwater. The surface map used for this effect is the texture called ind_2d in the archive OBJ_REGULAR.
Texture used for 2D distortion
When the camera is above water, there is also distortion of things under (and sometimes above) the water level. This effect uses the ind_3d texture in the same archive.
Texture used for 3D distortion
Often the effect applies to stuff that isn’t underwater, which results in an awkward look:
In fact, when the camera is far enough away from the water, the distortion effect is disabled, likely to reduce the occurrence of this issue:
However, even without the distortion effect the water looks much nicer on the Gamecube compared to the PC version. This is because there’s another effect applied to the water surface that the PC version is missing. The salt_tev02 texture included in texture archives for levels that have water is used as a surface map (possibly bump map) to make the water surface lighter or darker.
Texture used as a water surface map
By replacing this texture with a solid white color we can compare what the water looks like with and without the effect. When we remove the effect, the water starts to resemble the PC version a little bit:
Gamecube with bump mapping
Gamecube without bump mapping
PC + Gamecube textures (no fog)
Without the effect, the water texture is always bright, which can be problematic because the water uses additive blending. If the water covers other bright objects, it gets a “neon light” or “acid” look sometimes. Thanks to the bump mapping effect, these issues are less noticeable and the water blends much better in the Gamecube version.
There are other differences as well: the moving pattern of the water surface is a bit more complex on the Gamecube, and the UVs make the water surface texture appear larger than on the PC version. Also, fog makes the water much brighter on PC, so I disabled it for the sake of comparison.
It should be possible to restore the zoomed-in look and movement patterns in the PC version, and depending on how the surface map is done on GC, it may also be possible to apply it as a bump map to make a similar looking effect on PC. Maybe you’ll see that in the mod eventually. Also, the distortion effect could be replicated on PC via shaders, possibly even without the artifacts that can be seen with the Gamecube implementation.
That’s all for now. I’ll post more findings on Gamecube stuff when I get to work on it next time.
GitHub has locked me out due to Microsoft’s forced 2FA policy which I don’t want to comply with. As a result, I can no longer log in to the website to make pull requests, participate in discussions etc. However, at the moment I can still push to repos (wow, so secure huh?), so I can still work on SA Tools, the Mod Loader and other projects. They may pull the plug in the future but at least for now I can contribute to projects that are still on GitHub.
After being locked out I was able to make the following updates:
SA Tools
I added more complete support for reading and writing NJ and GJ files from various games. The update needs some testing so it will be in a separate branch for now.
SA Tools / Texture Editor
1) Unmodified texture data is no longer re-encoded unless the archive format is changed. Adding (instead of importing) textures will now add them as-is if the texture format matches the archive format (e.g. you can add DDS to PAKs or GVRs to GVMs).
2) You can choose between DDS and PNG for textures in PAKs.
3) If you open a single PVR/GVR/XVR texture, it will auto-add all other textures located in the same folder.
4) You can open and edit non-indexed PAKs (SOC folder).
5) You can save individual textures in their original format using the “Save” button.
6) Support for YUV422, Bump, 4-bit Indexed + Mipmaps, Indexed 8-bit + Mipmaps and ARGB8888 indexed PVR pixel formats.
7) Code cleanup, various bugfixes with texture encoding and decoding.
SADX Mod Loader
The game can now load textures in Gamecube GVM files without conversion. This opens up new modding possibilities, particularly for a project I’ve been contemplating to do for a while. I’ll introduce it soon.
Huge thanks to Exant, who decompiled original GVM loading code in SA2 PC, and Kell, who fixed the issues with mipmaps and paletted textures.
Microsoft, who acquired GitHub 5 years ago, are demonstrating their true intentions regarding the future of the site that used to be the largest hub of free and open source community projects.
I was a user of GitHub before Microsoft acquired it, and they have no moral right to impose their new rules and threaten to lock me out of my work if I don’t obey. You can debate the security, necessity and efficacy of 2FA in general or for GitHub in particular, but to sum up my thoughts on this measure: – I’m not going to use any form of 2FA for my account on GitHub; – I find forcing 2FA on long-term users, AND locking out those who don’t want it, unacceptable.
So, I have decided to leave GitHub permanently. I will not be coming back to GitHub even if they reverse the decision (though obviously they won’t).
As I am leaving GitHub, I will no longer be able to contribute to the following projects on the X-Hax organization: HD GUI 2 SADX Mod Loader / Mod Loader Common SA Tools and SA Tools Wiki SA Tools (research) SADX Modding Wiki Decompilation projects bass-vgmstream
Depending on what kind of “restrictions” Microsoft put on my account, I may also become unable to report issues or participate in discussions in the above projects after October 6th, 2023.
Leaving is not easy, and losing touch with the community and projects I’ve put a lot of personal time into building and improving sure hurts. Still, I hope you understand and accept my decision.
This is a list of all distinct Sonic Adventure (+DX) versions that can be obtained today as far as I know. Originally I wanted to make a branching timeline of SA1 builds, but I couldn’t find a good way to put it on a blog, and I also realized some builds, like the Autodemo, don’t necessarily fit in a single timeline, so here’s a list instead. There is also a lot of information on SA1 development on TCRF, which I recommend if you want a timeline of SA1 development with screenshots and other details.
Dreamcast builds
Let’s start with the original game on the Dreamcast. Note that I’m not including builds that we don’t have, such as the Tokyo Game Show demo and the version used for the Tokyo International Forum unveiling video (assuming the footage comes from a single version of the game).
Title
Version code
Release date
Date in IP.BIN
Comments
Sonic Adventure (Autodemo)
1.000
None
1998.10.16
Contains a mix of binaries and assets in various states of development. Some stage files were built for an older version of the main executable. There’s a lot of stuff written already about this version, so I won’t go into details. I have two copies of the actual disc, which looks orange in real life unlike the scan on Hidden Palace which looks more red, but that’s probably just a scanner difference. I dumped it, and the contents were completely identical to the Hidden Palace version.
Sonic Adventure (Japan)
1.007
1998.12.23
1998.12.10
The earliest official release of SA1 on the Dreamcast. Japanese language only. Some cutscenes have different camera angles compared to later releases. Some SET objects and camera setups are different in levels. This version has running “motion blur” effect for Sonic and Knuckles and the cowgirl billboard in Casinopolis, which were removed in later releases. This version also has some programming differences, such as collision for the burger shop man and different Lost World spikes behavior.
Sonic Adventure Taikenban
1.002
1999.??.??
1999.03.02
Demo version for the Japanese market. Mostly similar to the original JP version. The only version that introduces programming and SET layout changes to make the game easier.
Sonic Adventure – Trial Version for E3
1.000
None
1999.06.08
A version of the game with an in-progress localization. Contains an early version of the English script and different voice acting. Some character sounds are also unique to this build. The title screen has a completely different design, and the level select menu has difficulty ratings. Starting with this version the running blur effect is missing. Cowgirl is replaced with another billboard starting with this build. Some SET layouts have been updated to reduce Z fighting. Some cutscene camera angles were also updated starting with this version. The date in IP.BIN is interesting because it’s later than Limited Edition despite being an earlier version of the game. The actual game was likely compiled in spring 1999 (not earlier than March 12, as indicated by the strings present in 1ST_READ.BIN).
Sonic Adventure Limited Edition
1.001 and 1.002
1999.07.??
1999.06.03 and 1999.06.04
This version was available in the US for a short time before the final US release. Unlike previous versions, the level list in Trial Mode no longer matches the game’s internal level list. Internet features are replaced with a short demo. The Internet demo is also present (although not accessible normally) in all versions of the game after this one. This build has incomplete localization in languages other than English, and the menu to change the language of messages and voices isn’t functional yet. There are at least two variations of this build, however the only differences are between IP.BIN files, which have different dates, region codes and version IDs.
Sonic Adventure – Trial Version
Generator Vol. 1: 1.002
Dream On Vol. 2: 1.000
Generator Vol. 1: 1999.09.09
Dream On Vol. 2: 1999.09.30
Generator Vol. 1: 1999.07.08
Dream On Vol. 2: 1999.08.06
Demo version based on the US release. Unlike Taikenban, this demo doesn’t play cutscenes except those played after waiting on the title screen.
Sonic Adventure: Tournament Disk
1.000
1999.08.10
1999.08.10
A demo version used in an event called “Sega Dreamcast Mobile Assault Tour”. In terms of completion, this version is somewhere between Limited and final 1.004. Almost all binaries have the same content as 1.004 except different pointers to accommodate the recompiled 1ST_READ.BIN. There is no browser but there are references to the Internet demo like in Trial. Files for other European languages are not finished yet. Other differences are leftovers from the Japanese version or have to do with the game being a demo. More details on TCRF.
Sonic Adventure (US)
1.004
1999.09.09
1999.08.12
First American release. Mostly the same as Limited but with finished support for other languages. From this version onwards the game includes the TV Settings menu to select between 50 and 60 hz modes.
Sonic Adventure (Europe)
1.003
1999.10.14
1999.09.09
The first version that introduces an animated title screen. Some SET layouts were updated from US 1.004 with minor fixes.
Sonic Adventure International (Japan)
1.003
1999.10.14
1999.09.20
Mostly the same as the European release. Both Japanese and American SA1 websites can be accessed via the built-in browser.
Sonic Adventure International (Dreamcast Express Extra)
1.001
1999.??.??
1999.11.19
Included on the demo disc “Dreamcast Express Extra”. Unlike the other demos, this one comes with an animated title screen. Pressing Start takes you directly to Sonic’s Emerald Coast, which drops you back on the title screen after you beat the stage. Although only Emerald Coast is playable, the game includes all cutscenes and gameplay demos that play after waiting on the title screen, so you can see several Action Stages and Adventure Fields ingame. This demo lacks English HUD and menu textures, so the game will have visual glitches if the console’s language setting is not Japanese.
Sonic Adventure (US) – Sega All Stars version
1.005
2000.08.22
1999.10.05
Second American release based on European or International.
Gamecube builds
On the Gamecube we have two very interesting prototypes which fueled a lot of SA1/SADX research. Much of the knowledge on the game’s internal workings came from the first Preview prototype years before we got the X360 version with debug symbols. Apart from the prototypes, the builds on this platform haven’t been studied as thoroughly as the Dreamcast version. It is notable that the Gamecube ports have sequenced sound effects, which use a Gamecube adaptation of the MLT file format that was originally introduced in Dreamcast SDKs. Interestingly some character grunts are similar to the ones found in the E3 1999 version of SA1 DC, and some changes to assets are similar to the Autodemo and early prototype screenshots of SA1, but that’s a topic for another post. There is no doubt that SADX code is based on a later version of SA1, most likely 1.005 or International. Also, all versions of SADX have a leftover texture archive with title screen textures from SA International.
Title
Release date
Date in apploader.img
Comments
Sonic Adventure DX – Preview
None
2002.04.10
This version appears to be based on SA International and contains work-in-progress “DX” changes. Some features that were disabled in later builds are partially functional in this build. This version has a lot of debug functionality. The original game’s palette lighting system can also be activated in this version, although it doesn’t look correct. The Chao system hasn’t been reworked yet and is mostly functional and similar to SA1 DC. Although other languages are present, the game only works correctly in Japanese. This build has leftover binaries from an even earlier version of the port that hadn’t introduced the “DX” changes yet. Unfortunately we haven’t been able to boot the earlier build due to version differences between the REL files.
Sonic Adventure DX – Review
None
2002.09.05
Most “DX” features and redesigns have been finalized. The Chao system is a work in progress. There is also a Chao debug menu. Languages other than Japanese are functional. Like Preview, this version has leftover binaries from an older version of the port without the “DX” changes.
Sonic Adventure DX (Japan)
2003.06.19
2002.09.05
The first official release of SADX on the Gamecube.
Sonic Adventure DX (Europe)
2003.06.27
2002.09.05
Although the binaries were recompiled, there are no known differences from the JP release other than default language.
Sonic Adventure DX (US)
2003.06.17
2002.09.05
Although the binaries were recompiled, there are no known differences from the JP release other than default language.
Sonic Adventure DX (Gamecube Preview Disc)
2003.05.20
2002.09.05
A demo version included on the Gamecube Preview disc. Functions similar to the Trial version on the Dreamcast. This release and the Challenge Version are the only two versions of the game that use colored banners in the character select screen. The Start button is disabled during gameplay. No cutscenes are included, however the intro movie plays after waiting on the title screen. The music loops 3 times before the intro movie plays.
Sonic Adventure DX Challenge Version (Gamecube Interactive Disc Catalog Summer 2003)
2003.??.??
Catalog ISO: 2003.04.17 DX ISO: 2002.09.05
Japanese language only. The title screen has a subtitle that reads “Challenge version”. No cutscenes are included, however the intro movie plays after waiting on the title screen. This version has time restrictions, and the timer counts down instead of up. Otherwise this demo seems similar to the GC Preview Disc version except Sonic’s level is Speed Highway instead of Emerald Coast.
PC builds of Sonic Adventure DX (2004)
There are two distinct “base” versions of SADX PC – the original 2004 port and the “Dreamcast Collection” 2010 port. The 2004 port is where it gets really complicated as there were releases in different countries and the details on the actual differences are fuzzy. There are versions released in the UK, Germany, France, Spain, Italy, Hungary, Sweden, Australia, Israel, Brazil and Singapore, which may have minor differences. I know for sure the EXE in the Hungarian version is different from the “regular” European version. However, I must also say that the differences between these versions are so minor that almost all assets in sonic.exe are placed at the exact same addresses as the US version. One notable exception is the Korean version, which I have included as a separate entry in the table.
All versions of the 2004 port share the same features and downgrades. The 2004 PC port is based on the Gamecube port as it contains strings mentioning REL files. One interesting thing about the 2004 and later ports is that they use the blue water texture in Emerald Coast, which was used in prototypes but replaced with a green one in the final version on the Gamecube. The 2004 version uses WMA files for music and voices unlike the versions before and after it that use ADX. This port also abandons sequenced sound effects and switches to a different soundbank format containing raw PCM WAV files.
Title / Country
Release date
Comments
Trial Version B (Japan)
2003.11.21
Includes one level for Sonic, Tails and Knuckles. Unlike the Gamecube demo, this version doesn’t have colored banners in the character select screen and doesn’t play any cutscenes. The title screen plays a longer version of the main theme (normally heard in the main menu) on repeat.
Trial Version A (Japan)
2004.02.?? (before 2004.02.03)
Includes a level for each of the six characters. Other than that it is the same as the B version.
Trial Version A (Global)
2004.10.02
Same as the Japanese demo A but in English.
Japan
2003.12.18
The earliest full release of SADX PC. Japanese is the default language, but all other languages are also supported. The title screen, the intro and the main menu background are always in Japanese. This version comes with SafeDisc copy protection and hasn’t been researched much.
US
2004.09.14
This is the version of SADX PC used for research and modding.
Europe (UK)
2004.02.06 Multiple
Mostly the same as the US version except more advanced copy protection. There may be different protections (SafeDisc or SecuROM) in different releases. There was a protection-free re-release in “Sonic PC Collection” in 2009.
Korea
2004.07.14
A complete Korean localization of SADX PC, including all ingame dialogue, all menus and a colored manual. This version is unique in that it contains different assets translated to Korean, as well as various programming changes related to localization. It is also the only version of the 2004 PC port that has unique FONTDATA0.BIN and related structures in the EXE to support Korean. Voice language is English. Japanese voices are automatically replaced with English voices, although the actual files for Japanese are still included.
The new ports (2010 onwards)
In 2010 SEGA released a bundle for PS3 and X360 called “Dreamcast Collection”, which contains ports of several Dreamcast games including SA1/SADX. Although it is bundled as “Sonic Adventure”, the core game in these ports is based on the 2004 PC version of SADX. However, it does put back the original Dreamcast title screen with ripples. While they share almost all of the downgrades of the original 2004 PC version, for obvious reasons these ports have completely different rendering and sound systems that were developed by SEGA of China. They use shaders for character lighting and switch back to the ADX format for music and voices. Interestingly shaders and textures for water distortion are also included, which suggests that they were going to reintroduce Gamecube water effects, but there is no water distortion ingame. In addition, the soundbank format was revised, and sound effects switched from WAV to ADX.
These ports also introduce many additions wrapped around the original game’s systems, such as a texture replacement hook using DDS textures, support for achievements and online leaderboards, a different main menu system, new screens for credits, controls and tutorials, new fonts etc. Game Gear games are inaccessible (but still technically there), while Mission Mode and Metal Sonic are unlocked via a paid DLC.
This collection was also released on PC twice – in 2011 (physical) and 2016 (Steam). The 2016 version is known as “Dreamcast Collection Remastered”. Little is known about the differences between the 2011 and the 2016 versions, but on the surface they appear to be the same. The version of SADX currently available on Steam is the Remastered version. The Steam version comes with the DLC force enabled, and the Dreamcast title screen is inaccessible. If enabled via hacking, the DC title screen is a static image, although the model for the animated title screen is present in the binary.
These ports are the least researched and for the most part don’t present much interest. However…
X360 prototype builds
In 2020 several development builds of the X360 port were discovered, including a near-final build with debug symbols. The debug symbols have helped a lot in identifying assets and code in the PC version. I’m listing all known builds of the X360 version, including the final one.
Version ID
Build date
Comments
36
2009.12.15
The executable in this package is not the actual game, but some kind of X360 leaderboards and DLC test. Interestingly it does include shaders.
46
2009.12.28
Same as above.
79
2009.12.30
Same as above.
104
2010.01.08
This version is missing some features specific to the 2010 ports that would be implemented later, such as mipmaps (so in this build the game looks pretty much like the 2004 PC port), European language translations of CON_REGULAR_E.PVM and some logo screens before the game starts. The title screen is a static image, and the “Press Start” texture is from the Gamecube version. This build has a different version of the image used for the 4:3 border.
135
2010.01.22
This build introduces the animated title screen, more logos and a new “Press Start Button” texture. This version has a “Face recognizing” password screen which appears to be the developers’ attempt at a joke. Password: Sonikudamoxi This version is missing the 4:3 border image.
147
2010.01.29 or 2010.01.30
This version introduces files SOC_FONTDATA0.BIN and SOC_FONTDATA1.BIN, although they are also referenced in Build 135 which doesn’t have them. These files are used for the subtitle font in the final version. This version has the same 4:3 border as the final version. Password: Sonikudamoxi
209
2010.03.25 or 2010.03.26
Introduces automatic mipmap generation and a new font for the file select screen, as well as French, German, Spanish and Italian translations of CON_REGULAR_E.PVM. In all previous versions of the game CON_REGULAR textures were only in English and Japanese. Password: damoxifL
387
2010.08.01
No known differences from the final version. However, this build has a leftover “Test” folder that contains a PDB file with debug symbols, which makes it the most important prototype of the whole bunch. Before this build, all assets that were originally in the DLLs in the 2004 version were compiled into the main executable. From this build onwards they are split from the main binary again.
390
2010.??.??
Final version.
If you own a rare version of the 2004 port, let me know! The Korean version was a big surprise and very interesting to look at. Maybe there are more unique versions out there?
