Timology

I Have Downloaded some Atari 7800 roms at Atari Age. There are some Roms with .bin at the end not .a78. All these Cartridges are not working. .a78 is the only Format that MESS can Run. Can you help me??

Hello, I have some Atari 5200 roms with the same Title in 16k and 32k whats better 16k or 32 k. can you help me