IMTAS MCT-550 micro cassette record with calculator
One one side this is a micro cassette record and on the other side it has a calculator! The MCT-550 from 1978 calculators 8 digits precision and algebraic logic. It has 6 functions, 23 keys, and one of the early LCD (liquid crystal) displays which incorporated a yellow filter.
This is identical to the “Handy Business Machine MCT-550” and the “Radix MCT-550”