You can never boot GB or GBC games on a GBA flashcart.
Even though the GBA is backward compatible, the cartridge are not.
GB/GBC cartridge run at a different voltage, and when inserted in a GBA they trigger the different hardware mode to run those games.
I have a Flash2Advance pro, but the Sram is brocken, therefore I can't use it with regular GBA games that need to save to the battery.
Therefore I bought a GB Bridge, which is a sort of U-shaped converter that you can connect your flashcart to and slide it into the GBA, changing the voltage of the cart making it boot in GB mode.
I put all my GBC games on it(included Cannon Fodder) and they all work flowlessy as on teh real hardware.
However they never looked so good in the past, now that I have a backlite GBA SP.
Most GBC games don't even use a battery to save, they give you passwords, so I'm fine.
The GB bridge I believeonly works with F2A and the old vision-something card that are no longer in the market.
But if you could get this kind of equipment than you won't have to pray for an emulator anymore, but you will get the real thing!
Another cheap solution would be to buy real used GBC games, there were quite a few good ones, but not that many after all, and they must be really cheap these days, plus they look magnificent on the SP2 !
Just to remind you, GB-Bridge doesn't fit in the DS.
(since GBC doesn't fit in there either due to the shape of the cartridges)
I bought a GB-Bridge with my Visoly Flash Advance 256M card (for $150!!) oh so long ago. I got them from lik-sang.
I only used the GB-Bridge once for Zelda. Mixing GBA+GBÂ games on there is a little confusing, especially when trying to handle saves.
There was some .GIF that someone made a long time ago visually explaining how the GB-Bridge handles GBC saves. I'll try to find it.
I believe it's something like: the GB-Bridge uses the last (4th) slot on your card for GB/C saves. Not only that, but it divides the last slot into I believe 8 sections; one for each game. Or something along those lines.
The only problem I have with this set-up, is that I can't modify the palette of GB games the way I used to do it with a GBC(by pressing a combination of d-pad and buttons to get a different palette at the start up logo).
In fact I am stuck with only one ugly palette.But that does not matter because Goomba is more than capable of nearly perfect GB emulation, and it's even possible to change the palette at any time.
It's the GBC games that are best played with the bridge, to get 100% compatibility as they run on real hardware, not an emulator.
I also found some time ago an hacked GB loader for the F2A that used to give a large amount of pre-defined palettes to use with any GB mono games, but that wasn't really user friendly.
Any other option to get more colors out of it ?