I just bought this computer today and I want to test it to see if it works. Only problem is that I don't have any software for it to test it out with. I also don't have a power supply for it.

I have an Atari 5200 power supply. Can I use this with the 800?

If I turn the unit on without a cart or peripheral plugged into it, what would / should happen? Is there any built it OS that it should by default load up?

Also I'm missing some keys, there wouldn't be a place where I can buy replacement keys, is there?

I also need a picture (closeup) of the keyboard so I can tell where each key does where. I sort of dropped the computer and a lot of the keys fell out. OOPS!