Popular and affordable, the Epos-73A retailed at RUB 400 during the 1980s, easily outselling the comparatively unsuccessful Elektronika S3-27 model.
An eight-digit calculator with a vacuum fluorescent display, the Epos-73A was manufactured from 1978 at state union-subordinated plant No. 677, since renamed FSUE NPO Luch.
On top of the basic arithmetic operations, the device could calculate square roots and percentages, and change number’s sign, with designated buttons for each of these functions. To the left of the numerical keys, there was a separate four-key block for memory-related processes. The calculator is powered by a 220V mains supply.