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> I did some research and this seems to be an original idea. Why hasn’t anyone tired this before? I've done it. Making the emulator, debugger, and hooks to ext

• ggambetta 12y ago
  That's very impressive work. I really had no idea any of this existed before writing mine, and so far people have pointed out several instances of this applied to consoles (which I haven't explored at all), but none about PC games. I wonder why is this? Do consoles have higher-level APIs you can hook into that makes this more reusable across games - more similar to adding hooks to a game engine vs an individual game in the PC world?
  • byuu 12y ago
    Well, having a game under emulation gives you more control over what you can do, certainly. You now control the software and hardware. But I think most people also don't want to make enhancements that only work on a single emulator. And getting emulator authors to cooperate is like herding cats (which is why we are still using the woefully inadequate iNES header format in 2014.) So I could have made MSU1 run some 1080p video mode with a 2GHz simulated x86 processor, but it was important to me that the protocol be as simple as possible and exist in a physical implementation that worked on the real system. More along the lines of your example, my emulator core is completely abstracted to its own library and is GPL, so it would be quite easy to hook routines as you have to do things like hires textures even on the SNES. But there are some more extreme challenges to that than just identifying key functions, as the SNES renderer is very elaborate. I can't say I've specifically enhanced PC games, but I've definitely worked on translations of them from Japanese to English. There's definitely lots of fun tricks you can do outside of emulation, still. I usually write a debug process launcher that uses DLL injection, which is then followed by installing trampolines in various functions. We worked on a game called Heroine Anthem, where the movie file format was entirely custom. So we ripped the movie with screen capture software, subtitled it, encoded it to XviD (this was a while ago), and then ran our own DirectShow window to play back the movie in place of the originals. We also patched an online multiplayer game, Fuurai no Shiren, to add a new dialog to configure the server you connect to. We reverse engineered their protocol (their "encryption" was a strtr function on streams of hex values. Quite laughable.) and then created our own PHP server, called OpenShiren, so that people could run their own instances. Especially useful once Chunsoft shut their servers down. I've done far, far crazier things with manipulating others' applications, but since they weren't games, I won't elaborate on those here.
  • pmarin 12y ago
    There is a PC remake which follows similar approach: Abadia Del Crimen [1]. The author worked with the original binary to maintain the original logic of the game. The game first was converted from CGA to VGA and then he wrote a translator to covert the the original 16bit DOS code to 32 bit Windows with DirectDraw and DirectSound using only assembler all the time. [1] http://www.abadiadelcrimen.com/ http://www.abadiadelcrimen.com/
• Natsu 12y ago
  > In my case, I created some new I/O registers for the SNES. One set is called MSU1, which lets you read in up to 4GB from a data file, Was this what was used for the Star Ocean translation? I seem to recall that the translation hack for that was quite complex.
  • byuu 12y ago
    No, that translation was completed before I started on my emulator. Star Ocean has the SDD1 for graphics decompression and memory mapping, but I wouldn't say it was technically more difficult to translate than other SNES RPGs.
    • Natsu 12y ago
      I just thought of that because I remember reading how they couldn't fit everything into the ROM. Everything in that game was compressed and they couldn't find any extra room and it had to rely on an external graphics pack with emulator support is how I remember it.
      • byuu 12y ago
        So the history there ... Star Ocean was a 48mbit (6MiB) game, which was tied with Tales of Phantasia for the largest game ever officially released. But Star Ocean took things further than ToP, by using the SDD1 to allow DMA to transparently decompress data read from the ROM. The compression wasn't stellar in terms of size reduction, but it was wonderful in terms of having no CPU impact, as the SNES was a very slow CPU. The issue was that it was a really weird compression format. It uses golomb codes and prediction. So the ZSNES/Snes9X teams took a shortcut: they logged every time a DMA from ROM occurred with the SDD1 decompression flag set. Then John Weidman ran the same DMA transfers through his custom setup on real hardware and dumped the decompressed data to files. They packed that together and that's what was called a "graphics pack". The emulators then simply grabbed that already decompressed data. Think of it like using a giant 1000x1000 multiplication table instead of just learning how to multiply yourself. When it comes to translation, this wasn't any kind of a problem. If you needed to modify one of these graphics, you could bypass the SDD1 and transfer it as normal tile data. But for the most part, fonts and text weren't compressed in this way anyway. Eventually, Andreas Naive cracked the compression algorithm, and emulators today actually decompress the data without graphics packs. On that note, the same thing was done for the SPC7110 (used by Far East of Eden Zero), which took many years longer than the SDD1 to crack. Since that was cracked a while after the final release of ZSNES, they still need those graphics packs there. Now let's talk about the size: yes, Star Ocean was big. But space has never really been a limitation for SNES fan translations. Even without a memory mapper, it's very easy to fit around 96mbit (12MiB) of ROM data into the available memory map. You could very, very easily do 64mbit (8MiB) without any effort at all. It's honestly a bit of a mystery why some of the SNES coprocessors had any MMCs (memory mappers) at all, as they were wholly unnecessary. That said, you will often hear certain SNES fan translators mention the lack of space in games. And I will never understand it. They seem to want to enforce an artificial limitation on themselves to fit their entire translation back into the original game space; often sacrificing script fidelity, using stronger compressions that hinder game performance, etc. It really makes no sense to me. Yet the person who hacked Star Ocean was one such individual. If you want a fun anecdote about Star Ocean: I was the first to hack the game for an English fan translation, and was working with the person who ultimately translated the script. Unfortunately, I was an ignorant 14 year old kid and freaked out on him when I found out his translations weren't 100% literal (which in retrospect would have made for a terrible script), so he rightly told me to go fuck off. I eventually grew up, and we worked together much later on to produce the Mother 3 fan translation. But it's too bad, I would have really liked to have finished Star Ocean myself, but I wasn't mature enough to work with other people back then.