metal slug - neo geo cd

you suppose its some sort of protection? maybe it isnt exactly silence, but low freq shit that the ngcd verify's an gives it the go ahead for blood or english mode or whateva.
nope its just silence.....they use that track for bg silence during the game....strange but true, i replaced the silence with a simple muted track and got the same results....neo geo cd works kinda funny that way....they also seem to allways have a 600 k dummy file at the beginning of the cd data tracks...full of FFFFFFF or something similar.....wierd...
memory addresses. thats probably the protection

there use to be a couple ngcd rls groups around that were talkin about that. the protection was essentialy in ascii
actually there is no 1 single protection on this system, its got quite a few checks for different things....