Although I now have an Atari 800XL, it is not the one I had as a kid. This one is a latermodel because it has the Rev. C BASIC built-in. It is not modified in any way. If you zoom in on the picture below a bit, you’ll notice the Option key is somewhat worn out. This is pretty common because you have to hold down Option to disable the built-in BASIC, which is usually needed when running disk-based machine language games.