You mean the duty switching? Was that really so hard to figure out you had to make a thread about it?
well yhea its only been 11 days and im already covering my third song (which is this one).... im not really that knowledgable with everything yet. now how am i going to pass this over without actually copying the whole thing....
You should probably link to the song you are referencing. Like this but with square brackets: (url=http://something)linktext(/url) = linktext
For the sound you want, I think you're talking about an instrument with a changing duty cycle. You can control it manually with the Vxx effect, or as an instrument macro (turn on the Duty / Noise macro and type some values into the sequence editor ( e.g. "1 1 1 1 0 0 0 0 0 0 0 0 2" ).
If you really want to look deep into it, there's the NSF Importer that you can try on the Punch Out NSF (track 20). Or try the keyboard view and time expansion of NSFPlug.
I've attached a few seconds of Punch Out remade as an FTM as an example.
Holy crap, if I'd only reloaded the thread 10 minutes ago... (Of course during that time I made the actual instrument instead of just NSF importing...)