1984 -
Elektronika MK-54
A programmable calculator with reverse Polish notation, the Elektronika MK-54 came out of the Quasar plant in Kiev in 1982.
The scale on the monitor: 1:1
While its functional capabilities were very similar to those of the Elektronika MK-34, the MK-54 had a different case (later used for the MK-61), and ran on batteries instead of a power unit, cutting the price-tag by 20 roubles. It also featured unpackaged integrated circuits and had its two-position switch replaced with a three-position one to enable degrees to grads conversion. It has also been claimed that some later MK-34 models were able to support degrees to grads conversion by fixing the switch in the middle position, though this was never officially confirmed.
The Elektronika MK-54 was a second-generation programmable calculator with a twelve-digit vacuum fluorescent display, using eight digits for numbers. Although LCD screens were already widespread, these programmable devices still used the tried and tested vacuum fluorescent displays up until the release of the MK-86 in 1986.




Programming was based on 98 programme steps and 12 memory registers, as with Elektronika’s MK-34.

The device ran on three А-316 Quantum batteries (predecessors of modern AA batteries) or a D2-10M power unit.

It could run on one set of batteries for more than 3 hours.

Weight: 250 g or less
Dimensions: 167×78×36 mm

Sources: user manual, https://ru.wikipedia.org/wiki/%D0%AD%D0%BB%D0%B5%D0%BA%D1%82%D1%80%D0%BE%D0%BD%D0%B8%D0%BA%D0%B0_%D0%9C%D0%9A-54http://www.leningrad.su/museum/show_calc.php?n=159, http://electronika-5.ru/calc/index.php?page=base_item&mid=34.