Homebrew Emulation GameYob, a gameboy emulator for DS

[Drenn]

1st time using this emulator.
Realy good performance and i am realy happy with it.
But a bug that a user had posted here still persists in this version . In the Metal Gear Solid gbc game (as in every emulator i have tried on handhelds). The game crashes at the end of stage 3 when using the elevator .
if providing a save state helps uncover the bug i will gladdly provide one, just tell me where to send it

Keep the good work great job

A save state would be helpful. You should be able to upload it along with your post.

 

[soulrazor]

A save state would be helpful. You should be able to upload it along with your post.

Here it is. its from the US version of the game
Hope it can be usefull

 

[dickfour]

What are the chances this gets ported to other platforms? This blows the doors off every other gb emulator out there

 

[Canadacdn]

0.4.1 isn't working well for me at all. The touch screen menu seems to become unusable in some games shortly after you start playing and is only accessible by pressing the R button, which strangely will get the sound working again. Mario Land 2 is one game that has this problem.

 

[Drenn]

What are the chances this gets ported to other platforms? This blows the doors off every other gb emulator out there

Nah, most other platforms could run emulators with much better compatibility. This originally ran on a pc, and I still have an older version which runs on pc, but it doesn't have a user interface. I might port it to the 3ds if homebrew ever gets off the ground.

0.4.1 isn't working well for me at all. The touch screen menu seems to become unusable in some games shortly after you start playing and is only accessible by pressing the R button, which strangely will get the sound working again. Mario Land 2 is one game that has this problem.

Let's see if I understand correctly: soon after starting to play, sound hangs up, the touch screen can't be used to open the menu, and the X & Y buttons stop working. And 0.3 didn't do this? What system and flashcart are you using?

 

[Canadacdn]

Yeah, that's basically what happens, I never experienced this with 0.3 or any previous unstable builds. The X and Y buttons still work though. I'm running gameyob on a supercard dstwo.

Edit: my bad, the X and Y buttons in fact do not work.

 

[Drenn]

Yeah, that's basically what happens, I never experienced this with 0.3 or any previous unstable builds. The X and Y buttons still work though. I'm running gameyob on a supercard dstwo.

I experienced a similar problem a while ago, it had something to do with the sound code. But I thought I fixed it.
If you're willing to do a bit of testing, I'd like you to try this. When you enable the debug output it will print... a number. Under normal circumstances this number should be zero, or close to it. But you may find that at some point it increases to 60, at which point sound will stop working. I also wonder what happens to this number when the console is enabled and disabled.

Also... is the "Sound Timing Fix" enabled?

 

[MarkDarkness]

Thanks a lot for the effort Drenn and contributors. This emulator is so damn sweet. Having a blast since it was first released.

 

[Canadacdn]

I experienced a similar problem a while ago, it had something to do with the sound code. But I thought I fixed it.
If you're willing to do a bit of testing, I'd like you to try this. When you enable the debug output it will print... a number. Under normal circumstances this number should be zero, or close to it. But you may find that at some point it increases to 60, at which point sound will stop working. I also wonder what happens to this number when the console is enabled and disabled.

Also... is the "Sound Timing Fix" enabled?

Alright, I'll play around with it for a bit and see what happens. So far, enabling and disabling the console doesn't seem to do anything unusual. Sound timing fix is enabled.

 

[Sizednochi]

Is there any way to make scalling look more accurate, more "pixelated (example of what I'm saying)"? For me it just looks kinda bad even with the filter on, distorting most sprites. On some games it's fine, but in games like Mario Land 2 it just looks ugly. I'd imagine it's because of the bitmap rendering methods, but I was wondering.

 

[Arm73]

Is there any way to make scalling look more accurate, more "pixelated (example of what I'm saying)"? For me it just looks kinda bad even with the filter on, distorting most sprites. On some games it's fine, but in games like Mario Land 2 it just looks ugly. I'd imagine it's because of the bitmap rendering methods, but I was wondering.

It's because of the DS low screen resolution.
In order to achieve what what you are looking for , you'll need a display with at least twice the resolution of the original GB/GBC ( to display a clean 2:1 image), which unfortunately the humble 256x192 DS screen, just isn't capable of.
Therefore the implementation of filters, to try to alleviate the problem of an up-scaled image.

I'm using a DSiXL which is quite larger anyway, so I don't particularly feel the need of upscaling and I'm happy to play it at 1:1, however some GBC games look quite alright with it, so I guess it's a good thing that is there to begin with.

 

[Clydefrosch]

"Prefer GBC" and "Prefer SGB" act the same except when a game is both SGB and GBC compatible - for instance, Link's Awakening DX, and Pokemon G/S. Bios colorization doesn't count for "Prefer GBC".

Pokemon Blue should be gbc and sgb compatible too, right? but i only get to see gbc colors if i turn off sgb mode completely. both prefer options show me sgb colors.

 

[RowanDDR]

Very cool that "Hi-Color Mode" games such as The Fish Files and Addams Family now work. I don't think they worked in the last release, although they've been working for ages in the in between builds. From Wikipedia:

Hi-Color Mode
A few games used a technical trick to increase the number of colours available on-screen. This "Hi-Colour mode" is a mode used by the Italian company 7th Sense s.r.l. among others, and can display more than 2000 colours on the screen. Some examples of games using this trick are: The Fish Files, The New Addams Family Series, and Harry Potter and the Chamber of Secrets.[citation needed]

 

[Drenn]

Pokemon Blue should be gbc and sgb compatible too, right? but i only get to see gbc colors if i turn off sgb mode completely. both prefer options show me sgb colors.

No, Pokemon Blue is not gbc compatible. Its color palette is stored in the bios, which is why everything is... well, blue. Pokemon Yellow, on the other hand, supports both gbc and sgb.
If you can use the directional buttons in the bios to get different colors, then the game is not gbc compatible.

Very cool that "Hi-Color Mode" games such as The Fish Files and Addams Family now work. I don't think they worked in the last release, although they've been working for ages in the in between builds. From Wikipedia:

I think I had them working in 0.3, although it's been improved since then.

 

[Searinox]

I've got a 100% reproductible guru meditation by first loading pokemon crystal and then super mario land 2.

 

[Drenn]

I've got a 100% reproductible guru meditation by first loading pokemon crystal and then super mario land 2.

I'm not getting a guru med error... but I'm getting a crash with flashing red lights on the bottom screen. Can you tell be the values of "pc" and "lr"? (I assume you're using 0.4.1)

 

[Searinox]

pc(top): 1FFF0000 addr(top): 33208E6E

lr(middle right): 01000CE0
pc(middle right): 02003EF0

 

[Drenn]

Here it is. its from the US version of the game
Hope it can be usefull

MGS is pulling some weird shenanigans... it jumps to an address using the contents of the wram bank register as one of its bytes. I think it's an oversight, actually. MGS, I am disappoint. Oh well... it's fixed in the new build

pc(top): 1FFF0000 addr(top): 33208E6E

lr(middle right): 01000CE0

pc(middle right): 02003EF0

Alright, I think the problem is that the external ram bank didn't have its default value set properly. It should be fixed now.

 

[Searinox]

External RAM? Do you mean it uses the SRAM save as a pagefile? It would make sense since SML2 uses so little data(lives, coins, unlocked levels x 3) that the devs decided to use the extra space as RAM?

Are you going to compile a new build with the fix?

 

[Drenn]

External RAM? Do you mean it uses the SRAM save as a pagefile? It would make sense since SML2 uses so little data(lives, coins, unlocked levels x 3) that the devs decided to use the extra space as RAM?

Are you going to compile a new build with the fix?

When I push an update to github, the build on dropbox is (usually) updated too. It's the third link in the first post and it has the fix.
I guess I wasn't very clear when I described the problem: by external ram I mean sram. Gameboy games can have a maximum of 4 "banks" of sram. Pokemon Crystal has 4 banks, while SML2 has 1. What I assume happened, is that Pokemon Crystal had, say, bank 3 loaded when you exited and opened SML2. The initialization routines should reset this number to zero, but they didn't. So SML2 tried to access memory that it didn't have.