I've owned a Yamaha DX100 synthesizer for decades and never really had a strong grasp as to how the heck you build sounds with it. The last few months I have been immersing myself in FM synthesis and I think I finally have a handle on the concept now. Here is set of twenty-four patches that I created:
They all sound better and less brittle with a little reverb and chorus, but you get the idea. I especially like "Astro Pong" and "LoocySynth". If you like what you hear, you can download a .WAV file of the cassette dump and load these patches on to your DX100/27 via the cassette port hooked to your PC. Just make sure your PC's volume is turned way up or the DX won't hear the data stream.
UPDATE: I have finally saved these patches as sysex files (see below). Here is information on loading sysex on to a DX100 (also contains separate sysex files for each of the individual patches).