Brief history of OSs evolution (1)

In principle the user was also a programmer early in '60 mainframes started to provide some "advanced features" like input/output management, the user should still be a programmer (1965: Multics) in '70 the concept of OS is clear and some "modern" OSs are available, over all Unix (1973: rewritten in C), but let's remeber at least VMS too if mainframes are the "real computers" for people that work with them, some new "toys" are created for people to learn and have fun: personal computers