If it has a standard gameport adapter you could probably solder directly to a arduionobo teensy:

http://ps-2.kev009.com/eprmhtml/eprma/h929.htm

Might even be enough space to do this inside the Toshiba,
https://catskullelectronics.com/arduinoboy-lite

THAT BEING SAID - why not just use a tracker on the toshiba? Or an lsdj midi into something like the volca fm

Really appreciate the info man.

To answer your Q, I'm looking for a way to have a tracker interface on a handheld device in my hands while still controlling an OPL3 chip. Problem is, my live sets often involve me flailing and moshing directly in the crowd, so I don't want to be flying around with a nice OPL3 laptop in my hands. I figure the best solution is to have an expendable device with a tracker directly controlling the OPL3 from afar. Thus I have the mobility/freedom of playing with lsdj + the ability to still 'play' an OPL3 laptop live. I know I could also just create a SB16 card based synth but time=money and having the ability to track with the Toshiba normally at home without having to buy another PC dedicated to tracking is a + for me

Any idea what programs the creator of the Frankenkorg is running at the 11:47 & 19:52 marks in the demo? Seems like I would need something like that on the toshiba

Thanks again for the help dude, it's much appreciated.

http://ps-2.kev009.com/eprmhtml/eprma/h929.htm

Might even be enough space to do this inside the Toshiba,
https://catskullelectronics.com/arduinoboy-lite

THAT BEING SAID - why not just use a tracker on the toshiba? Or an lsdj midi into something like the volca fm

Basically, I am interested in configuring a new live setup involving a Gameboy with LSDJ MIDI out/Arduinoboy sequencing the internal synthesizer of a Toshiba Libretto 50CT.

Think opl3toshiba's FrankenKorg 800 but with an external tracker (lsdj on gb) controlling the Toshiba's synthesizer instead of a Poly800 being directly wired to its MIDI interface. The Gameboy will only be sending MIDI to the toshiba's MIDI interface. No audio out from the Gameboy itself.

My main question is, what software would I run on the Toshiba so that it acts as a software synth instead of a tracker? Basically, what software is opl3toshiba running in the video linked above? Is using an external tracker as a sequencer for an OPL3 laptop even possible in this manner?

On the hardware side, I believe I've figured out how to get MIDI in to the Toshiba (solder gameport midi adapter to the internal midi interface in the Toshiba - just have to see which pins on the card are MIDI I/O)

Thanks! Love you!