for the genesis stuff, i use my nomad running on battery power (least noise of any genesis unit) and record using an 1/8" stereo miniplug male to 1/8" stereo miniplug male cable (the same thing on both ends) which plugs into my sound card. i use cool edit pro 2.0 to record, denoise (there is still some noticeable noise in the recording, even though it's from a nomad) and then normalize it (to make sure it's nice and loud). mp3 encoding is done on my mac with itunes, but i imagine itunes for windows would behave exactly the same way in that regard.
stuff from the snes, saturn etc uses the cable or adapter m.midget was talking about that goes from rca audio (red and white) to 1/8" stereo miniplug.
most of the stuff in the most recent update that wasn't just ripped from cd (so the rockman complete works music) probably involves the most complicated process of all. there is a set of utilites called
psxvideo, and in that set of utilities is a program called xaex.exe (try saying that five times fast). this program is able to talk directly to your cd-rom hardware to copy the normally off-limits bgm.xa file off of the game disc onto your hard drive. the reason it has to do this is because the .xa file is written in what's called mode 2, or "xa" (extended architecture) format. if windows or os x or whatever tries to copy the file, it can't do it, because it's expecting it to be a mode 1 file. the catch to all this is that you have to have
actual dos running on your computer, not windows nt or otherwise emulated dos. this means you need windows 3.1, 95 or 98 in order to use the program. nt, 2000 and xp just won't work.
anyway, once you have the file off, you can use some of the other utilities in the package to extract the waveforms inside the xa file. usually the xas are eight tracks (numbered 0-7), so eight different wave files pop out. then it's time to use cool edit pro to separate the different songs inside each track. sometimes there is only one song per track, but even then the song will go on for like six or seven minutes, and get really boring, so i make it a policy to start a 10 second fade at the second repeat (so the third iteration) of every song. you will notice that this rule applies for virtually all of the newer-sounding stuff on the site.
hope that answers your question.
