If you relax laptop to mean functionally portable, then reasonable commercial variations existed since the early 80s. Not with a clam-shell form factor, but de

If you relax laptop to mean functionally portable, then reasonable commercial variations existed since the early 80s. Not with a clam-shell form factor, but designed to travel with you. By late 80s you had things that looked a bit like current laptops, e.g. NEC ultralight.