1975 -
Elektronika S3-07
In 1976, Svetlana (St Petersburg, then-Leningrad) started manufacturing the Elektronika S3-07 calculator. The calculator had large keys, and early models displayed numbers with a smooth backlight, which was removed in later models.
The scale on the monitor: 1:1




Elektronika S3-07 is similar to Elektronika 24-71.

The calculator has as few as 15 keys, which means that some functions had to be combined in one key, namely „+ =„ and “- =„, as well as „х -:-“. To multiply 2 by 3, one needs to press “2„, “х -:-„, „3“, „+ =„, and to divide 2 by 3 the sequence is “2“, „х -:-“, “3„, “- =„. Addition and subtraction follow the model of Elektronika B3-04, i. e. to subtract 3 from 2 the key press sequence would be „2“, “+ =„, “3″ and „- =“.

The device is equipped with a rare IV-2 eight-digit vacuum fluorescent display. The same display is installed in Elektronika 24-71, which was modelled after Elektronika S3-07.

The calculator is powered by a 220V mains supply. Power intake — 25 VA or less. The maximum time of continuous operation was 24 hours.

Dimensions: 227✕133✕61.5 mm.
Weight: up to 1 kg.

Sources: http://www.myadel-gimnaz.by/node/44, user manual.