bank switching is the general idea. both NES and GB/c, for example, used cart-side memory controllers to greatly expand the ROM access capabilities of the system. Really about half the systems I can think of use some form bank switching to get past previous limits. I see no reason at all why people view NDS's 128mb as a solid limit when we see our backup carts accessing far more every day without breaking a sweat. Yes they're more expensive to make than standard carts, but probably not by much at all.agreed. The DS may only have been designed to be able to address out that far but nothing says that's a limit. The path is well worn with all the 'backup' cards we have. There's no real rule that says a legit cart can't do it too. On previous systems, similar techniques were used quite a lot to increase space.
No, the current maximum for a DS card is 128 megabytes, or 1024 megabits.
Curiously, reaperman has said "On previous systems, similar techniques were used quite a lot to increase space.", without mentioning what techniques these are. Do you mean bank switching?
@OP: FFanboy.
so exactly why are we now seeing address limits as unbreakable barriers? An effect of getting used to games on optical media?
old FF games are certainly possible. lame, but possible. is this the best you can dream up? Let the past stay in the past where it belongs. There's no (technical) reason that I can see why commercial carts don't come with microSD slots for saving downloadable content. MMO gaming in dynamic worlds even seems possible. why not have a big dream instead of a crusty old RPG you played through and got sick of?
Go back and play FFVII some time. you'll see that it belongs in the past, and resources are better spent on the future.