For that project to work, you have to replace the brains of the PicoCalc with something that can run Linux, so you might as well just connect the display of a T

For that project to work, you have to replace the brains of the PicoCalc with something that can run Linux, so you might as well just connect the display of a Ti-84 up to a Raspi with an adapter board and advertise it as "running Linux".