The MK-52 is the first Soviet micro calculator with non-volatile electrically erasable memory (PROM, type KR1601RP1 with a capacity of 4 kilobits, the number of rewriting cycles is 10,000), ensuring security for programs when the power is turned off and the functions of the clipboard are performed.
BRP-2 «Astro» (Russian: БРП-2 «Астро»), with a set of programs for navigational tasks, information about which was published in the Marine Digest (Морском сборнике, in Russian) No. 12, 1988; .