Whodaimen said:
So I take it I can keep as many roms as I want on my slot-1, and flash the current one onto the 3 in 1 whenever I want?
Yes.
QUOTE(Whodaimen @ Apr 25 2008, 01:48 AM) So its essentially a blank GBA cart with an internal battery, ram + rumble?
Are there any limitations? I assume all the Pokemon games will run fine?
It doesn't have a clock, so the pokemon games that use the clock won't work exactly the same way as they do on the real carts. There are patches for Ruby and Sapphire to enable the time based events without the clock, but there is no patch for Emerald. AFAIK Fire Red and Leaf Green didn't have a clock in the first place. You can use the 3-in-1 to migrate your pokeymans to a patched Diamond or Pearl rom on the slot 1 cart, but you cannot migrate them to a retail D/P cart. Same goes for the other features you enable by playing D/P with a GBA pokemon game plugged in.
The 3-in-1 only has 16MB of RAM, so 32MB games must be written to NOR in order to play them. When a game is written to NOR, the 3-in-1 works just like the retail cart would (with the exception of the clock of course). You can boot it from the DS menu just like a real GBA game, even without the slot 1 cart inserted. You can still run other games from RAM with GBA ExpLoader when a game is written to NOR.
The rumble feature must be enabled each time you want to use it; once the power is turned off the 3-in-1 goes back to acting like a GBA game until you enable the rumble again. GBA ExpLoader can enable rumble mode, but only if you have one of the supported slot 1 carts (R4, M3 Simply, M3/G6 Real, SCDS1 and others). Some slot 1 carts support the 3-in-1 directly so you don't need to use GBA ExpLoader to enable rumble mode (EZ-V, CycloDS Evolution, Acekard 2/RPG, possible others). If you don't have a supported slot 1 cart you can still use all the GBA features. Rumble cannot be used with GBA games, only DS games and DS homebrew.
If all that seems complicated, don't worry. It's easy to figure out once you actually have the cart to play with.