This is something I worked on for quite a while. I have a Casio CT-370 keyboard from 1987 that I use on a lot of my recordings, it was used extensively on the albums Atlantis Falls and Polybius. I took the synth and sampled every single sound inside on all 5 octaves the keyboard has and painstakingly made them into an sf2 file using Swami on Linux.
I went through and recreated every single preset on the synth, as well as all of the percussion sounds. In addition to that, I created 16 of my own presets using samples from the synth. All of the music in the above vid are from the soundfont.
Now this synth can be used freely in the world of MIDI and is completely cross platform. Sf2 files, or Soundfonts, are an old way of collecting multiple samples into one file and can be played in any Soundfont player on Windows, Mac or Linux. LMMS features a great sf2 player, and Linux has Fluidsynth, others exist for both Mac and Windows that are free of charge. You can now add a full Casio CT-370 to your arsenal of sounds!