When I was in high school I learned to program on the M-20 ... In the group of programmers at Institute of Theoretical and Experimental Physics, where computing work was done on nuclear physics on the M-20, they came up with arrays, lists, the need for subroutines and more. One of my teachers, Georgy Adelson-Velsky came up with a hash memory. Details can be found in another of my teachers - Alexander Kronrod "Conversations about programming". Even before Dijkstra's basic principles of structured programming was known, Alexander Brudno published the book "Programming in meaningful notation." There was also created the first chess program ... The chess program ITEP, the predecessor of Kaissa fit in memory of M-20, namely in 4096 cells, each of which has a 48-bit ...