Mizutani created the sound driver at Natsume and the music was programmed in binary/hexadecimal.
Mizutani created MIDI files. Then he loaded his MIDI files into a debugger where he would convert the MIDI file to text. Next, he would modify the music in the debugger. Then he would initialize it. Mizutani used instrument samples from many Roland devices such as the S-330, D-550, SC-55 Mk II and Yamaha TX-802.