Terminated: unknown
This calculator has many nice functions, including grouped functions to operate on fractions, and a nicely big backspace key.
This calculator operates on solar energy only, but fortunately needs little light to operate.
The "OP1" and "OP2" keys provide a form of semi-programmability. For instance, when you want to add the number "13/2" to a series of other numbers, simply type "+ 13/2 OP1". Now, when you type "5 OP1", the result will be the outcome of "5 + 13/2". Thanks, Koen van Driessen.
A peculiarity, inside on the circuit board of this calculator, there's a LED. This LED operates as a zener diode to regulate the solar cell's power output (thanks Joerg Woerner).