http://gb98.exile90.com

Well, Hello and Welcome,

I put together this little emulator for the Nintendo Gameboy. It's very early work, and doesn't emulate everything, but some games do run on it, and on my P166 they seem to run at about the same speed as the original Gameboy

Adam Polanski

QUICK NEWS:

• 7th Jan 1999 - Version 0.05c Added CGB Emulation. (public release delayed because of Adam's computer problems...)
• Dec 1999 - Version 0.05 Release Fixed several instructions, push, pop, call, ret were actually broken. Also fixed (E8) ADD SP,*. That gets some gbdk examples to nearly work correctly ;). Soon will come the day when gbdk compiled programs will work on my emu, then I can start writing a few programs myself..
• Dec 1999 - Version 0.05 Private Beta 2 Added screenshot function. Rewrote cpu emulation engine again. Added more MBC support. Also did some preliminary work on a debugger which isn't functional yet. Redid layering on the gfx engine, now sprite/background/window layers should display correctly.
• Dec 1999 - Version 0.05 Private Beta 1 Fixed speed issues when running on a pentium 400 it should play at the real Gameboy speed. Added LCD blur function, game saves are in now too. TIMA emulation was buggy, that's now fixed. Found I was emulating the CPU flags wrongly, that whole CPU emulation needs to be recoded, I've got most of that done now but I'm just trying to tidy up the code so I know what's supposed to go where. Oh, and there's a palette editor in there too.
• 20th Dec 1998 - Version 0.05a released. Fixed several instructions, push, pop, call, ret were actually broken. Also fixed (E8) ADD SP,*. That gets some gbdk examples to nearly work correctly ;). Soon will come the day when gbdk compiled programs will work on my emu, then I can start writing a few programs myself..
• 20th Dec 1998 - Adam is looking for informations/documents about Gameboy Color emulation. If you think that you can help him please contact Adam. Thanks. KEL out.
• 04th Dec 1998 - Well, I just wanted to let you know that Adam is STILL alive, and he's working VERRRRRY HARD on the next version of GB98... (I've got 0.05 to test a few days ago, so expect the new version verry soon). KEL out.
• 14th Nov 1998 - Version 0.04 Beta 2 released. Did more rework on the interrupts, color palette got changed because I fixed another bug in the frontend.
• 14th Nov 1998 - Version 0.04 Beta 1v released. Did some major rework on interrupt generation, and fixed the RETI instruction.
• 14th Nov 1998 - Version 0.04 Beta 1u released. Debug message box. TIMA emulation. Few other minor fixes & updates.
• 12th Nov 1998 - Version 0.04 Beta 1t released. Removed 2 crash bugs. Pokemon Blue does not work with this emu yet. I'll get to fixing this and more bugs when I have the chance to find out why...
• 11th Nov 1998 - Version 0.04 Beta 1s released. I've been rewriting some major chunks of the emulator, to fix the sound bugs. Now the sound emulation still isn't perfect, but a lot of bugs that used to stop the emulator from working have been removed. It's also running a little quicker too.

HISTORY:

• 7th Jan 1999 - Hmm, wierd year, I haven't quite gotten used to typing 1999 yet. Anyone remember the TV series 'Space 1999'? Hmm, maybe I'm just far too old. Anyway added CGB emulation just to please all those out there who wanted it. Added a splash screen, and now I'm happy to say I'm now getting a little help from other people, thanks to you all. I will be adding plugin support soon, so anyone will be able to write their own plugins for the gameboy emulator, so if you want better sound, then somebody else can write it.
• 20th Dec 1998 - Version 0.05a released. Wow over a month since I updated this section. Lots has changed and I added, rewrote loads of things since the last update. I did say my next set of fixes may take a while, well I didn't lie. Saving screenshots is in, so is a much improved cpu engine (my last one), funkier MBC emulation (but still not perfect), and I've started adding a debugger which doesn't do anything yet!!
• 14th Nov 1998 - Version 0.04 Beta 2 released. Fix a frontend bug which broke the colors in the emu, more work on Timer interrupts and trying to find out what causes some roms to just plain die. With the lack of relevant documentation on the GB hardware, this is a difficult task and it may take a while.
• 14th Nov 1998 - Version 0.04 Beta 1v released. Now a lot of things that didn't work, now work a little better. Many things still don't, I ran Metroid for a short while and it seems ok, previously it didn't get past the title screen...
• 14th Nov 1998 - Version 0.04 Beta 1u released. Added a debug message viewer. This displays messages which the emu generates while running a ROM. This is mainly used by me to see what is happening in the emu as a rom is running. One odd side effect of this release is, there's more code but the exe file is smaller.. I managed to strip about 26k of useless stuff out of the emu code. TIMA emulation is in too, this means that in Dr Mario, and Tetris you will get random blocks, rather than the same one. It may affect other games too, but I can't test all of them now can I?
• 12th Nov 1998 - Version 0.04 Beta 1t released. Removed 2 crash bugs. Pokemon Blue does not work with this emu yet. I'll get to fixing this and more bugs when I have the chance to find out why...
• 11th Nov 1998 - Version 0.04 Beta 1s released. During the last few days, I rewrote the LCD handling which was a minor speed improvement (10-15%). Also tried fixing the sound system. Well, I ended up deleting just about all of the old sound system and rewriting it to use DirectSound. This was my first ever DirectSound experience, and I can see why Microsoft did things the way they did, but I hate it. It's far too slow and clunky, but then they wrote windows so what should I expect. Anyway, it's done now, and I'm pretty sure it works for 99% of machines out there unless I missed something?!!! ;-) Over the next few days, I'm going to be improving the sound emulation to the point of perfection I hope. Then I'm gonna work on some of the things that stop the emulator working for some games.
• 4th Nov 1998 - Version 0.03 released. More preparation for the new assembler Z80 emulation engine going in. Currently everything is in C, so this should speed up emulation by about 20%. After that is in, I'll work on speeding up the LCD refresh, and fixing some window/sprite priority bugs. The new Z80 engine will hopefully cover all opcodes more accurately than my C implementation. The C implementation was hand coded, the assembler is generated. Drag & Drop Support. Should now handle file associations too.
• 1st Nov 1998 - Hey there, I'm still working on getting the next release out. It'll contain some more bugfixes, better sound, better ROM handling, and more importantly I'm speeding up the code. I may make an interim release later this week, depending on how my time gets used up.
• 25th Oct 1998 - Sorry for the delay, many things have happened to me this past week or so. Now I've added sound emulation and fixed many bugs which were apparent earlier. Most images should now work, though some don't. I've been experimenting with some cool new ideas to put into the emulator, which explains why there are more menu options, although they're all unavailable. These are just because they don't work properly enough as yet. I'm still working on it!
• 13th Oct 1998 - Did the Load ROM dialog, now I can load whichever ROM I please. I was fairly happy with it, and so I'm now going to release this current version to the public. Yes, it isn't perfect, there are bugs in it, but not any that should cause a major problem.
• 12th Oct 1998 - Stopped working on sound, decided to make the load ROM options. I feel that being able to select a ROM is a little more important than sound at the moment.
• 11th Oct 1998 - Windowing and controls added. Made a start in the sound area, but still no sound.
• 10th Oct 1998 - Running with BG and sprites. Almost full emulation of Gameboy Instruction set (after a few nasty surprises, why don't people document those wierd opcodes?). 501 opcodes emulated. Currently the emulator doesn't take any input, no sound emulation, but it does run under Win32. I'm planning on using DirectX (Bleurgh!) to make things a little more rational (If that's at all possible). When I put some control in, then I'll put it up here for download. Please don't ask me for ROMS, as they're copyrighted by whoever owns them (probably the big N). So I'll ignore requests for those. Also, I'm fully aware of a lot of bugs, and once I have most of those under control, I'll start taking comments from people.

DOWNLOAD

Version 0.05c