MICROPROGRAMA is a program with few lines of code and, fundamentally, that executes one or a few functions. It is what was formerly denkminated RUTINA, and that was invoked by the programs, for example the writing routine, that wrote the text of the value in a computational check, or the date routine, which formatted the date or converted it to text. . Moreover, there were sub-routines, with very elementary functions, such as formatting, arithmetic calculation, verifier digit validation or key checker.