Keith Shaw, IT World, Watch people explain UNIX in 1982, here. Lorinda Cherry is here. I think the dancers at the end are rob and pjw.
The film, “The UNIX System: Making Computers Easier to Use” was aimed at students who were interested in engineering, math, computer science or other sciences, AT&T says. The film includes some brief interviews with Dennis Ritchie and Ken Thompson, who in 1969 created the system that would become UNIX. The film also features a discussion about spell-checking and grammar correction that many copy editors of today would find fascinating. For a “what the heck is that?” moment, jump ahead to the 22:33 mark, where the credits of the film include a computer-graphics dance/yoga sequence: