I think I’m not going to be able to fix this without the hw debugger. Debugging in ProjectABE is really limited. All I can tell is, for some reason, zboy is busy executing a whole bunch of NOPs.
I just noticed that MBC2 is really similar to MBC1, and a few MBC2 games are small enough to fit. I made a small change to the converter so that it would run these games as if they were on an MBC1 cartridge and it worked!
Some working MBC2 games that might be of interest:
- The Final Fantasy Legend
- Wave Race
- Ultima - Runes of Virtue
I am going to hazard a guess: Nintendo had copy protection that required the Nintendo scroll down text in the beginning of execution. IDK how this is bypassed in the homebrews but possibly this is sonewhat related.
In any case this is not a very high priority issue
I don’t know if it’s true for Gameboy ROMs, but I remember reading that GBA ROMs required the bitmap for the Nintendo logo to be present at a certain position in RAM, as well as for the game to be checksummed somehow.
(Found an article about it here.)
May or may not be related to the problem at hand, but interesting nonetheless.
The Gameboy BIOS checks the cartridge ROM for the Nintendo logo, before letting the game boot. This isn’t exactly copy protection, it’s forcing unlicensed developers into a trademark violation. That nostalgia-inducing logo at bootup exists because… lawyers. >_<
Anyway, this should not be causing the problem here because:
1 - The emulator does not include the BIOS, so there is no logo check.
2 - The games in the link actually have the logo
3 - Some licensed games crash similarly
This is so great! it is like a small xmas powering up my pokitto again.
A free hardware debugger is on the way, from what I remember.
Probabily we’ll get a nes emulator soon
You’ve been planning this all along, eh?
That’s right, @jonne made sure I (and anyone within earshot) was hooked to the patriotic little guy from the moment I opened the box.
Incidentally I started writing an M6502 emulator the other week, but I got sidetracked.
(I started getting too focused on the memory allocator because it was more fun than the opcodes.)
We also need an atari 5200 emulator
6502 will get you on the road towards NES, and Atari 5200, and…
MOS Technologies KIM-1
Atari 7800 (game system)
Atari 2600 (game system)
Atari Lynx 1 and 2 (game systems)
Acorn System One
PC-Engine (Turbo Grafix 16) (two 6502s)
OSI Superboard 600 / UK 101
I was hoping to work on an original game next.
With the gameboy emulator we now have plenty of puzzle (Sokoban, Snoopy, Tetris, Dr Mario), RPG (Final Fantasy Legend, Ultima), sports (tennis, football, golf, basketball, golf) and platformers (Mario, Castlevania, Prince of Persia).
Now I’d like to play some action/fighting games. Preferably without the Pokitto being encumbered by having to emulate another system.
On the other hand, we could really use a C+±based Pokitto emulator. I wrote ProjectABE’s Pokitto core using WebAssembly, which is an immature tech and definitely not appropriate for emulation (evidenced by Chrome’s constant crashing).
As for console (Nes, Atari, etc) emulation: their screen resolutions are higher than the Pokitto’s. If you think stretching up with nearest-neighbour is ugly, just wait till you try stretching down. >_<
Might be better to go with Gamegear and Watara Supervision, instead.
Edit: VIC-20 looks doable, at first glance.
Oh, Vic was my first computer (I still own a couple…) it had many great games, like Jeff Minter games. They had excellent gfx and sfx effects. I believe Pokitto could handle emulating the audio also.
The 176x184 resolution would fit to the landscape layout of Pokitto with very minimal borders.
Edit: Other my favourite games: Frogger, centipede, jetpac, choplifter.
One little snag: has anybody tried connecting a PS/2 keyboard to a Pokitto, yet?
The Atari Lynx is out. Requires too much RAM and has too many custom chips.
One of the early Tamagotchis might be possible if there’s enough info going around.
When I hear tamagotchi and hardware I think of only one person: @Mr.Blinky.
To be honest though, I think we should be aiming to create more unique games rather than emulating old ones.
I agree, there really is a million plus one other consoles for emulations who will do it better anyways. Pokitto as an educational tool should focus on native games with free source code to allow studying and tinkering. And new games will bring in more people, that’s what got me sold (on Arduboy, which lead me to Pokitto).
The Tamagotchi rom is about 1mb of seperate files, iirc. It’s much simpler to emulate and probably doesn’t change memory banks often, the virtual memory idea might work well enough. It’s documented and there’s a reference emulator available, so it might be worth a shot if anyone really wants to do it… although I do agree with the point that we need more unique games now.
I totally second that. One thing that makes me a bit frustrated, is that working on Pokitto (shipping, taxes, platformio, tracker, pokittolib changes etc.) leaves me very little time to work on any of the many ideas I have. Maker Faire Rome is coming up & christmas season so additional content would be great to have.
USB keyboard also possible