How many MB are ROMS?

like nes, snes, game boy, nintendo ds, master system, game gear, and mega drive

It changes depending on the game. SNES can be a few KB (1024KB in 1MB) or up to 256MB easy.There is no set size.

well whats the max the files can be? i am just wondering because i just bought an acekard 2i for my dsi.

I can't remember if the max of the NDS cards are 512MB or 1024MB(1GB)

that big... i thought that mb for games and mb on computers were different...

nope. Cartridge sizes are stated in Mb (megaBITs), while computers use MB (MegaBYTES). 8Mb = 1MB.

I haven't really been paying much attention to the last 1600 or so releases, but I thought the largest DS rom was still only 256MB.

It still is. There's still how much the DS can address to, I doubt they would release that information publicly.

I was guessing and guessed wrong. I was under the impression that the biggest games were 256, but there was room for more.

biggest untrimmed room for DS is 256.Most game stay at 64 mb.
Some large games get 128 mb.
Simple games and all are usualy 32 mb.
We actualy got very... but VERY few exceptions that reach 256 mb. (I belive, I rarely see one at least)