One thing I will say about the JAIR is that this is definitely an intermediate build. Maybe I'm slowing down in my old age, but this took me about 8 hours to build up. Not only are there literally thousands of solder joints to make, but they are close together and the lands are generally very small making it difficult to make contact with the land and the pin with the iron at the same time. Even with my usual 1.5mm chisel tip. Not a beginner build.
That being said, it offers a heck of a lot on a single board.
Here is a shot of it mostly done. Only have some jumpers, connectors, LEDs and RAM to add after this.
Note the butterscotch brown chip to the left of the 8080. Its a Bulgarian 8224 clone. I could not find a reasonable source for a genuine Intel chip, so took my chances on this item and got a couple of them for $1.69 apiece.
I could not find the RAM chips at DigiKey, but found higher spec'd NEC D43256BCZ-70Ls on eBay that were supposed to be NOS and were only $2.99 each from a local supplier. However, this is what arrived.
Not only were these NOT NOS, but it looks like they were pulled by an angry gorilla using his teeth.