Comic-Kaze:
Flavor might have some information on the multicarts.
I don't have one, but I know someone that does and they did some work on it.
As far as I can tell, it's somewhat similar to how the GameBoy Color writeable Bung carts work.
All the ROMs are right on the cart, and I think they're uncompressed. That's why they stick out of the NGPC so far. They need a longer cart to fit in the extra memory.
The makers of the cart wrote a menu program that lets you select a game, and that is what loads first when you turn it on. Then, when you select one of the games, the cart remaps its 0 offset to something else. Here's a quick example of what it could look like.
0x000000-0x0000FF Menu
0x000100-0x2000FF Game1
0x200100-0x4000FF Game2
So, when you turn it on, Menu boots. Then, if you select Game2, then the cart remaps some stuff and just adds 0x200100 to every address you request from now on. So, to the NGPC, the cart looks like Game2 is inserted.
It's the same way that the GBC flash carts work, and the same way the GBA carts work. Unfortunately, when they made the NGPC flash carts, they didn't include this type of functionality. That's why I wrote the NGPC Multi-ROM Menu. It seems very silly to use an entire 32M flash cart for a single tiny little freeware demo. Now, I think you can put every demo available on a single 16M cart. Though, I haven't tried lately. frown
<small>[ March 11, 2003, 08:51 AM: Message edited by: Flavor ]</small>