Ripping Questions

[Yawackhary]

I need help with ripping. I want to do backgrounds in Genesis games, but am lost on how to get the right image size. I use Kgens since it has layer disabling and try to get the backgrounds but come across a couple of issues. One, not the whole background is right there in front of you and requires scrolling forwards or up or even down within the level to get the whole thing. I can't imagine going through that and getting the perfect whole image of the background. 2nd problem, the resolution. I take screenshots and they're always 320x240 when a window or 640x480 in full screen. That can't be right. I want the exact size as the original picture is in the game rom. I see a lot of backgrounds that are ripped properly on this site have a typical size of 256x256 or 256x128 etc.. How do you go about getting the original resolution?

Getting the right resolution coupled with getting the whole image if it's not just right in front of you without moving around the level more just confuses me. Is there a way to rip straight out of the rom that's more typical for getting the proper rips, or some technique I'm missing?

Thanks for any help.

This is going to seem a long answer but I split it so it is more easily readable. The backgrounds that are ripped from the Sonic games (Sonic 1, 2, 3&K, CD and Crackers) used tools such as Daimzean's gpSonic Level Ripper or SonED2 which can dump tiles into chunks which you can see there. These chunks aren't actually what is stored in the ROM but they are far more useable.

As for other games, I decompressed a couple (Revenge of Shinobi and Castle of Illusion) and they use a limited tileset even smaller than the chunks. These games use something called the Nemesis compression which is quite common but to extract them you need a decompressor (also knowing common line too) and afterwards a tool like TileMolester or TileGGD for the decompressed ROM. Some games that have it uncompressed like Mega Turrican also have either what I just mentioned or similar to the Sonics. However many MD games are compressed or stored strangely, in the case of backgrounds most of them are compressed.

As for GensKmod, make sure there is no stretch option enabled but the things you said are quite common since they run at game resolution and the tiles in the games are much much less (usually 8x8, 16x16, 32x32 or a variation of that). Some backgrounds here are also maps. There is a VDP option though if you want to see the tiles in the stage (CPU, Debug, Genesis, VDP if you want to access it).