The Casio HL-801 appeared in 1979, and it was made in Japan. The screen is an early LCD - these can be recognised by the yellow filter over them, which made these early versions easier to read.
It's 137mm high by 75mm wide, and tapers from 18 to 10mm in thickness. It takes two AA batteries in a little compartment in the back, behind the screen.
It turns on and off by an on/off sliding switch to the top left of the button pad. And much more cannot be said of this fairly pedestrian calculator. Sadly, what could once be mad wonders of engineering were now slowly turning into, well, things like this. Little did this little calculator know that its LCD screen was an omen of an age of terribly boring, gray screens... it is not to be blamed, friends.