This talk traces the history of educational technologies in the age of film, from roughly 1920-1990. It focuses on what became known as the “audiovisual” industry: slides, filmstrips, and sixteen millimeter sound motion pictures. These machines and their materials were introduced into classrooms in the 1920s and draw on larger trends in technology and industry. Educational technologies blossomed during World Who War II and took on new forms during the Cold War. Though the industry disappeared in the 1990s, it provided a foundation for today’s digital technologies and offers instructive perspective on today’s debates. This talk traces a history of the teacher-student-hardware-software nexus that came to characterize instructional settings (in both schools and industry) from the twentieth century to today.