Not mainframes as such, as it was all part of an engineering degree at a time when microprocessors could handle 4 bits a time or just possibly 8 bits. I think at the time FORTRAN was about the only engineering oriented programming language. Now there seem to be lots of programming languages, although Python seems to me to be the most popular and widespread.
I expect COBAL programmers are very rare and command high salaries maintaining legacy systems.
I expect COBAL programmers are very rare and command high salaries maintaining legacy systems.