Atari 5200 Rom question

[Draugr]

Hi,

I downloaded a few roms for the Atari 5200 to test out the emulator on my PC. I am a little confused by the roms as there are multiple copies of each. Let me list a few of the same roms and perhaps someone here will know the difference and be able to explain them to me.

 

Congo Bongo (1983) (Sega) (U) [b1] <---- This is a 32k file

 

Congo Bongo (1983) (Sega) (U) <---- This is a 16k file

 

Does anyone know why there seem to be 16 and 32k versions of a lot of the Atari 5200 roms? Is the 32 better than the 16k versions? If so what is the difference? Also, if you look at the end of the top file there is a [b1]. What does the b1 mean? beta 1? I have no clue and would like to know what it means. I assume the (U) means US ans there seems to be (U) or (PAL) on a lot of the roms I see.

 

There also seems to be a few roms with [o1] and [a1] does anyone know what these mean?

 

I'd appreciate any help that anyone can give me here.

 

Sincerely,

John

[Nukey Shay]

http://games.compufer.com/emulation/rom-codes.html

[CPUWIZ]

The reason why they are different is because they were likely dumped by 2 different people. Either that or someone padded one of them to work with a certain emulator.

[DEBRO]

You probably see 2 versions (16K and 32K) because how the cart was dumped. For instance, Congo Bongo is a 16K game. It may have been put on a 32K cart where the code was mirrored. If you were to disassemble the code you would find that pages $4000 - $7FFF are the same as pages $8000 - $BFFF.

[CPUWIZ]

 

 

For those that are interested, Congo Bongo resides in the memory area of $4000-$7FFF and has an entry (reset) vector of $6000.