The ultimate Atari 400? Well, that would be 48K, a monitor jack (S-video, etc), and a replacement keyboard! How close to the 800 can we come? Those 3 things!   But what about the keyboard? It's never *really* going to equal the 800's great keyboard, but how close can it come? What is (was) the best aftermarket 400 keyboard replacement? They still come up on Ebay from time-to-time. Sometimes it's just the keyboard, and other times it's a 400 with the keyboard installed. However, it