This reflects the American adoption of personal computers pretty well. Most High Schools did not have personal computers until well into the 90s, but some had them in the late 80s. Similarly, universities in the early 90s did not have availability of personal computers to the degree math professors were all able to do calculations on them (to say nothing of the state of mathematical software at that point).
A number of personal computers in the Soviet Union were created, such as the MIR series were developed in the early 70s and late 90s, but commodity hardware didn't really kick in until the early 80s.