Research data from investigating Chocolate Doom OPL MIDI playback. dosbox-trace DOSBox patch and script to monitor Vanilla Doom OPL register writes and interpret. genmidi Script for parsing and converting contents of Doom GENMIDI lump oplinit Linux program to initialise Adlib card and play a tone. scale Constructed MIDI file to play each note in sequence in order to determine the register writes for each note. droplay Test program for playing back DOSBox raw OPL files. volume Examination of how scale level values are affected by menu volume setting.