This thread I'll dedicate to DSiWare designed to launch older DS flashcarts on the 3DS/n3DS. (and by old, I mean VERY old stuff. Stuff my TWL Slot-1 Launcher fails to work for)
This is separate from my TWL Slot-1 Launcher due to the fact that this works a bit differently and each launcher (if there are more I get working in the future) are specific to their flashcart and can't be used to launch slot-1 in general. Unlike TWL Slot-1 Launcher, if you intend to use this on emunand, you must have the DSiWare app in question installed to BOTH emunand AND sysnand!
But remember, you only need patched TWL_FIRM on emunand if using CIA of patched TWL_FIRM! Unless you are using rxTools of coarse. rxTools currently has the new TWL_FIRM patches that this needs. (that's o3DS exclusive though at the moment as rxTools doesn't yet have support for patching TWL_FIRM/AGB_FIRM of n3DS)
The above video shows the ORIGINAL R4 working on a n3DS/3DS for the first time! The original R4 has not worked even on the DSi! So that cheap 4/8 dollar flashcart that's still for sale in some places is now compatible with the 3DS using this launcher! Note this is a WoodR4 firmware launcher, thus you need WoodR4 files installed on your R4!
Download Link:
WoodR4Launcher.rar
It installs like any normal CIA. (Set destination to NAND if installing with FBI). Once installed, insert your R4 and boot this app. It will then start up the WoodR4 menu and games will be loaded from your R4's MicroSD card.
I will post launchers for other carts if and when I can get them converted and confirmed working.