NerdTracker II was originally a DOS-only tracker for the 2A03 (8-bit Nintendo CPU). Much of the old-school original NSFs where programmed on this. NT2 is a piece of history.
Fortunately, thefox has recently programmed NT2 for Win32 -- rejoice!
Make sure you download the "ASM Replay Code" from the official homepage of NT2 to compile .NED (NT2 files) to NSF.