Terminated: unknown
NASCO is not a calculator company but a retailer. This is quite likely an OEM model by another brand, I have not yet found which brand. Zero hits on this model using Google reverse image search, not even this NASCO version.
The P/NP key key can be used to switch printing on or off. This is indicated by "PRT" or "NOPRT" on the LCD. Still, when set to "NOPRT" the printer prints "0 C" wasting a little bit of paper.
The ON/OFF key looks like a tumble switch which in fact it isn’t.
The ON/OFF key and the AC key are protected from pressing them accidentally.