Hey Koh, if you're still interested in trying this one out, I did a bit of looking around.
The system in question is the Atari 800. There's an emulator for it named, rather creatively, Atari800. I checked the ROM site I normally use, and they have it, so the ROM itself shouldn't be too hard for you to find even without me giving a link to it.
Still want to give it a whack?

