This calculator (better said, portable computer) was sold either as a kit, to be assembled at home, or preassembled, Either way it provides the same functionality.
More functional details can be found on the Datamath Museum site here.
My device had of course bad batteries inside and they have been removed. Luckily, the batteries did not have a major leak, therefore the inside of the machine is pristine. The calculator works when powered from a lab power supply as can be seen; I did not try the included power supply, it very likely contains capacitors that are no longer in good shape. The original calculator came also with a 12V adapter, mine is lacking that.
The documentation is included.
