Right around the time the original Mac came out, so did a card for the Apple II to use the same mouse. Other emulators have supported it for a while using an imperfect HLE of the 68705 MCU on the card which showed occasional glitches. Because we love low-level emulation, I sent a card Down Under for Guru to dump the MCU program, which he kindly did and here's the result:
Note that certain elements of the GUI are clearly from late 1982/early 1983 Mac prototypes rather than the final look and feel that shipped almost a year after this. (Note also the innocent use of "Aids" not long before that became a loaded word).