This past year I took a chance on an eBay auction that featured an Atari 400 with the aftermarket B-Key keyboard. For those that aren't familiar with the Atari 400, it shipped with a membrane keyboard. Although it was pretty good for being a membrane keyboard, it wasn't as good as a real keyboard. Companies came out with keyboard upgrade kits. The less expensive kits were simply keys with stickers that you placed on top of the membrane keyboard. The best bang for your buck was the B-Key keyboard, which replaced the entire keyboard.
The auction didn't state the amount of memory in the 400, but I took a chance that whoever upgraded the keyboard would have upgraded the memory to 48K while the machine was disassembled. Unfortunately, that was not the case. This 400 only has the default 16K of RAM.
A couple of months ago I ordered the 48/52K upgrade card from tf_hh over at AtariAge. At the time I was planning on using one of Bryan Edwards' UAV kits to add composite/s-video out. That was, until I started looking at the Super Color CPU card.
The Super Color CPU card is a replacement CPU card for the 400 or 800 line of computers, incorporating Bryan's UAV kit. My Super Color CPU card came in today, and I'm super excited to upgrade my 400.
Christmas break starts in a week and a half, and I can't wait!