The Soemtron 220 is a peep behind the Iron Curtain, to see the state of the East German electronic calculator industry in the early 1970s - this machine is dated April 1972.
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 Friden EC 130.
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.