I remember reading somewhere[0] that they were used in the early days of Super Nintendo development due to similar chipsets.

[0] http://www.patpend.net/articles/ar/sil10.html

Good thing you inherited some software with it, and that it works.

I would suggest applying some Google Fu to find a user group that you can trade with.

If you are a Linux user, you can probably use it as a terminal - connected via serial.