The plan was that the "Acorn 1" was a CPU card to be used in a rack-type system, the keyboard/display/tape card was an add-on to turn the CPU card into a stand alone system. My school bought the Acorn-1 with keyboard/display assembled into a card sandwich and I spent many happy hours programming it for parents evening displays etc
I remember how much more "powerful" it felt than the MK14 (Which I had also had access to because one of my teachers let us use his) but I was also aware it was a more expensive beast than the MK14.