The Yamaha PSS-140 was my first musical instrument, purchased as a gift for me by my grandfather when I was little after he saw me delight in toying with his PSR-85. I still have it, and it still works except for a few keys in the top octave!

If any of you can relate to my nostalgia for this keyboard or any of the others in the title, you will be delighted to learn that Plogue Art et Technologie in Montreal have created a painstakingly-accurate software emulation of the YM2413 (aka OPLL) FM chip that powered those 5 Yamaha keyboards. This 2-operator FM chip was one of the lowest-cost FM chips ever produced by Yamaha, and Plogue's VST perfectly recreates the unique lo-fi character produced by that cost-saving design. Plogue's software version is called chipsynth PortaFM.

For me, it's an absolute joy to be able to get hands-on with adjusting the parameters on each operator, to play it using a full-size FSX keybed with velocity sensitivity and a sustain pedal, to be able to layer multiple instances for increased polyphony (the original chip only supports 9 voices), and to easily route it through effects on the computer.

Figuring out how to recreate something like the PSS-140's strange "Fireworks" patch was one of the first things I just had to do:
$77 $21 $07 $87 $13 $44 $0F $FF
(Paste this into the software to give my attempt at Fireworks a try.)

A free demo (limited to 4 minutes of use with no saving) is available for download on their website, and the full version can also be purchased there for $29.95 USD.

There is also a video on their YouTube channel demonstrating a comparison between the emulation and the original chip:

Finally there is also an album which has been released on Bandcamp with music from several artists highlighting chipsynth PortaFM: