Soemtron 220 Calculator
It is core memory based with discrete transistor logic and Nixie tubes, all built on a die cast aluminium chassis with die cast outer case panels.
Although 1972 was well beyond the dawn period for electronic calculators in the West, this machine most resembles first generation dawn period machines such as the IME 84 or the Olympia RAE machines.
Operating the Soemtron 220
The Soemtron 220 uses conventional arithmetic entry and has fixed, switch selectable decimal point. It is 4-function with two memories. Perhaps reflecting the late era of its manufacture, it has few quirks or error modes.