Elektronika MK-47

© Sergei Frolov A rare image of an MK-47!

© Sergei Frolov Another tantalising view!

The microcalculator MK-47 has identical functionality to the Elektronika b3-21. In addition, it allows storage of programs of up to 60 steps on magnetic mini-cards. Writing and reading of the information are carried out by setting a special switch located under the indicator, near the power switch.

For a brief period during the late 1970s, calculator manufacturers experimented with the storage of programs and/or data on small magnetic cards. Several well-known Western machines include the SR-52, TI-59 from Texas Instruments, and the HP-65, HP-67 and HP-41C (with a card reader extension) from Hewlett Packard. Storage of programs on these cards removed the need to re-key programs when they were needed, and actually quite a neat solution to the problems of memory-size limitation and the loss of memory contents when the machine was switched off (though TI and HP independently introduced CMOS-memory models to solve this last problem).

The Elektronika MK-47 is currently the only known Soviet calculator which used magnetic cards, and its design was probably based heavily on the TI and HP machines mentioned above.