About Pokémon games I'm not entirely sure, because they have to be patched in order to work as the 3in1 doesn't have an internal clock.
That information is wrong.
The game itself will work, except time-based events won't work at all, just like on the retail carts when the battery has ran dry.
QUOTE(how_do_i_do_that @ Apr 7 2010, 10:19 AM) DS connectivity, that depends on the DS flashcart if it can connect without truncating data. Some trimmers also cut out the DS wireless stuff at the end of a rom, which is bad if want such capabilities later one to work. That is why some here recommend you not trim a rom at all. It is also recommended that you NEVER get a rom from a source that pre-trims it for you, you do not know if the person used a trimmer that cuts the wireless stuff out. Helping you find such a source is unfortunately not allowed, your on your own for that.