There were two memory upgrades. The first was a card that plugged into the motherboard. The other one was an expansion module that plugged into the side of the computer (and multiple of those could be used). My PCjr had 384k of RAM, using both the internal upgrade and one sidecar.

I never bothered using the keyboard wirelessly. The cable was good enough and it saved on batteries. I was fortunate in that I had the revised keyboard, not the original chiclet keyboard.