SD2SNES, emulators and other possibilities

[omg]

Hi everybody. I have a SD2SNES cartridge. It’s fun. It’s the ultimate cartridge for Snes. Thank you so much for this awesome product and it awesome firmware!!

I like also the GBA games. I play it on my GBA, my DS, my Gamecube and also with emulation on my raspberry.

Iwould want to play GBA games on SNES but the only one product os the super retro advance... it’s not the better product for image... and it’s impossible to have it.

So I ask me about the SD2SNES...

Do you think that this cartridge can play emulators (GB, GBC, GBA or other)
Do you think that a new Everdrive for SNES can be create to play these games on SNES?

Thanks a lot.

[Gumball]

Hi everybody. I have a SD2SNES cartridge. It’s fun. It’s the ultimate cartridge for Snes. Thank you so much for this awesome product and it awesome firmware!!

I like also the GBA games. I play it on my GBA, my DS, my Gamecube and also with emulation on my raspberry.

Iwould want to play GBA games on SNES but the only one product os the super retro advance... it’s not the better product for image... and it’s impossible to have it.

So I ask me about the SD2SNES...

Do you think that this cartridge can play emulators (GB, GBC, GBA or other)
Do you think that a new Everdrive for SNES can be create to play these games on SNES?

Thanks a lot.

To put it simply no. There was talk of people wanting the SD2SNES to emulate the super gameboy but I really doubt the fpga on board is capable of doing it. As for gameboy color or gba? not a chance. I'm sure people alot more knowledgeable about the subject can explain why. The super retro advance is literally just a GBA clone system on a chip inside a cartridge. all it uses the snes for is controller input and power. The thing doesn't even use the snes to output video requiring it's own 3.5 mm jack to composite out cable for video out.

From what I understand first the snes is not powerful to emulate any system you mentioned not by any chance at all. If you made a cart that did it using an FPGA like the many FPGA clone consoles we have now like the analogue nt mini or super nt the snes wouldn't be doing any the work. The cart would be cause it would essentially just be one of those systems crammed into a cart. Only power and controller input would be used from the snes. At that point why would you even wanna go through the trouble of developing such a thing when you could just buy a flash cart for the system you want do that? I understand wanting to have everything one on system. It's convenient but what you're suggesting isn't just practical.

I will end this by saying first and foremost I am not a programmer or hardware designer of any kind. I'm sure anyone with the expertise and knowhow can explain in better detail if there is any hope or not for anything you suggested. Anyway I encourage anyone who is capable of this kind of stuff to always be striving for more cool and interesting ideas and am grateful to be able to partake in there hard work. You guys are legends in my eyes keeping these old systems alive.

[TomKeller]

A couple of years ago someone asked ikari_01 in a german forum if it would be possible to emulate the GameBoy or even the NES inside the SD2SNES FPGA - his answer was (sorry for my bad translation):

For the NES it's impossible or close to impossible. The Super Gameboy may be possible... but you would have to take a look, if the FPGA resources are enough for a Gameboy. The Super Gameboy doesn't just contain the Super Gameboy ROM, but a complete(!) Gameboy as well (well... without an LCD and without buttons ). Still someone has to write the Gameboy in HDL.

The second challenge would be the video transfer. Since the system is 'emulated' inside the cart audio and video somehow need to get to the multi-out . Audio isn't a problem at all since you can send it analogue via the cart slot. Video is a big problem, cause you need to send it digitally. Gameboy seems to be simple: the picture is relatively small and only has 4 colors.

Gameboy resolution: 160x144 pixel
color depth: 2 bits per pixel (4 grayscales)
amount of data per frame: (160*144)*(2/8) = 5760 Bytes
The SNES is able to stream around 6 kB data per DMA inside the vblank into the VRAM - so it's a tight fit.


But with the NES you'll reach the limits. While using some rasterisation tricks the picture can contain 64 colors simultaneously... and even more while using emphasis bits. Resolution is higher as well. Since you can only have 4, 16 or 256 colors on the SNES you'll have to use the 256 color mode.

NES resolution: 256x240 pixel
color depth: 8 bits per pixel
amount of data per frame: (256*240)*(8/8) = 61440 Bytes
As you can see: you would need 10 frames to send one NES frame - which doesn't make sense .


Without any conservative transmission techniques (prerendered frames, pixel by pixel) and with some smart HDMA tables you may be able to outsource some of the rendering work to the SNES PPU and only have to stream tile and palette data. Maybe a compromise between the CPU via S-CPU inside the SNES and PPU emulation via SD2SNES would be possible. But that's some kind of complexity i wouldn't wanna think about right now.

[Gumball]

A couple of years ago someone asked ikari_01 in a german forum if it would be possible to emulate the GameBoy or even the NES inside the SD2SNES FPGA - his answer was (sorry for my bad translation):

For the NES it's impossible or close to impossible. The Super Gameboy may be possible... but you would have to take a look, if the FPGA resources are enough for a Gameboy. The Super Gameboy doesn't just contain the Super Gameboy ROM, but a complete(!) Gameboy as well (well... without an LCD and without buttons ). Still someone has to write the Gameboy in HDL.

The second challenge would be the video transfer. Since the system is 'emulated' inside the cart audio and video somehow need to get to the multi-out . Audio isn't a problem at all since you can send it analogue via the cart slot. Video is a big problem, cause you need to send it digitally. Gameboy seems to be simple: the picture is relatively small and only has 4 colors.

Gameboy resolution: 160x144 pixel
color depth: 2 bits per pixel (4 grayscales)
amount of data per frame: (160*144)*(2/8) = 5760 Bytes
The SNES is able to stream around 6 kB data per DMA inside the vblank into the VRAM - so it's a tight fit.


But with the NES you'll reach the limits. While using some rasterisation tricks the picture can contain 64 colors simultaneously... and even more while using emphasis bits. Resolution is higher as well. Since you can only have 4, 16 or 256 colors on the SNES you'll have to use the 256 color mode.

NES resolution: 256x240 pixel
color depth: 8 bits per pixel
amount of data per frame: (256*240)*(8/8) = 61440 Bytes
As you can see: you would need 10 frames to send one NES frame - which doesn't make sense .


Without any conservative transmission techniques (prerendered frames, pixel by pixel) and with some smart HDMA tables you may be able to outsource some of the rendering work to the SNES PPU and only have to stream tile and palette data. Maybe a compromise between the CPU via S-CPU inside the SNES and PPU emulation via SD2SNES would be possible. But that's some kind of complexity i wouldn't wanna think about right now.

Thank you for this. It explains it much better than I ever could. I think to put it layman's terms the fpga in the sd2snes just doesn't have the resources needed to emulate or I simulate an entire console even if it's just an nes let alone a gameboy advance. The GBA may seem similar to an snes in visuals but the hardware in that sucker is pretty robust compared to the snes.

[Eyedunno]

I think to put it layman's terms the fpga in the sd2snes just doesn't have the resources needed to emulate or I simulate an entire console

No, to put it in layman's terms, the SNES itself doesn't have anywhere near enough bandwidth to stream NES video.

So even if the SD2SNES could emulate an NES or whatever, some pretty crazy tricks would be needed to get around the fact that you have ten times less video bandwidth than you need, and more likely you would need a way to output video directly from the SD2SNES itself (cf. the Super Retro Advance's video output on the cartridge itself).

[Gumball]

I think to put it layman's terms the fpga in the sd2snes just doesn't have the resources needed to emulate or I simulate an entire console

No, to put it in layman's terms, the SNES itself doesn't have anywhere near enough bandwidth to stream NES video.

So even if the SD2SNES could emulate an NES or whatever, some pretty crazy tricks would be needed to get around the fact that you have ten times less video bandwidth than you need, and more likely you would need a way to output video directly from the SD2SNES itself (cf. the Super Retro Advance's video output on the cartridge itself).

Right thanks for the clarification. Even if someone found a way to do it. It really doesn't sound all that practical to be honest.

[supersign]

What TomKeller says and there's this from discord:

ikari_01 on NES support:

well uh
yes and no
it might be possible to get something working but there's no straightforward way to get the picture into the SNES at sufficient speed
I can feed audio directly, but not video
now PPU2 has a secret mode where you can feed it 15 bit digital video
but of course it would be impractical to cut up the snes
lol

ikari_01 on Super Gameboy support:

OTOH Super Gameboy might not be too far out of reach
as it already works in "real life" through the cartridge bus.

[Greg2600]

Been saying for years now, would be cool to see more FMV ports of some kind, like Roadblaster.

[Gumball]

Been saying for years now, would be cool to see more FMV ports of some kind, like Roadblaster.

That would be pretty awesome. I wonder if Dragon's lair could be done.

[omg]

Thanks all for your replies.
I bought this week an Retro advance Cartridge to play gb gbc and gba games.
I wonder that a day, star ocean will be translate in French.

[dreimer]

Funfact... Super Gameboy enabled games had 16 colors out of a 52 colors palette at one time, so the calculation is wrong above. Seems like there are some tricks already in use by it then

[Jegriva]

Funfact... Super Gameboy enabled games had 16 colors out of a 52 colors palette at one time, so the calculation is wrong above. Seems like there are some tricks already in use by it then

AFAIK, the Super Game Boy enabled games are "colorized" by the Snes, not by the SgB cartridge.

[Missingno255]

Do you think that this cartridge can play emulators (GB, GBC, GBA or other)

Keep dreaming. The SNES doesn't have the power to play games with more than 10 objects on screen without extreme amounts of slowdown, let alone emulate a GBA. Not to mention, the extremely limited FPGA space to work with, even with an upgraded one with more space.

GB and GBC? Theoratically possible. Get SGB2, and cut the plastic tabs out.

[FeverDrive]

GB and GBC? Theoratically possible. Get SGB2, and cut the plastic tabs out.

I think the Super Gameboy 2 isn't compatible with GBC games.

[Jagasian]

GB and GBC? Theoratically possible. Get SGB2, and cut the plastic tabs out.

I think the Super Gameboy 2 isn't compatible with GBC games.

Early GBC games that had a grey plastic cart were backwards compatible with SGB.  Clear plastic GBC games were not backwards compatible.