Genesis Roms on Dreamcast w/Lemec

[joeblo55]

i'm a noob here, and i would appreciate it if someone could answer a few questions for me. in regards to lemec and genesis roms, what are the three variables at the top- mode, skip, and sound, for?
for mode i can choose 0, 1, 2, or 4
for skip, 0, 1 or 2
and for sound 0 or 1

also, is there any way to save your game? i see that there's a resume game option when you start the game, but it's always greyed-out. thanks!

lastly, is there a FAQ for this thing? all the options at the initial screen are confusing (i.e. 1st_read.bin, ginreset.bin, ginsu.bin, and on and on) what are all those for? sometimes i click on one and the screen just goes black and nothing happens!