Elektronika B3-34

Model numbers do not follow any special order: MK-54 is a slightly upgraded version of B3-34 and MK-56 is its desktop copy, while MK-61 and MK-52 are somewhat more advanced calculators with more operations and even EEPROM (MK-52 only).

Despite very limited capability, people managed to write all kinds of programs for B3-34 and its later successors, including adventure games and libraries of sophisticated calculus-related functions for engineers.

Hundreds, perhaps thousands, of programs were written for these machines, from practical scientific and business software, which were used in real-life offices and labs, to fun games for children.

[citation needed] This series of calculators was also noted for a large number of highly counter-intuitive mysterious undocumented features, not unlike the "synthetic programming" of the American HP-41, which were exploited by applying normal arithmetic operations to error messages, jumping to non-existent addresses and other techniques.

[citation needed] A number of websites provide the source of hundreds of programs for these calculators, technical documentation, lists of undocumented features and stories about them.

Some Soviet hackers managed to modify B3-34 into digital multimeters, control interfaces for model railroads, added tape storage devices and other peripherals.