From video surveillance to online teaching, from drone warfare, highway management to telemedicine: closed-circuit images take up multiple spaces today. Despite being quotidian, their history remains largely unknown. The project’s goal is to fill this gap by providing the first study of audiovisual closed-circuits (AVCC) in the longue durée. It scrutinizes the closed-circuits’ diversity between the 1930s and the 1990s and develops case studies from the USA, France, the UK, Germany, and Switzerland - countries crucial for the development of closed-circuits and providing access to resources for writing the history of a medium whose images were conceived as instruments rather than representations. Distributed under Industrial Television and CCTV (for closed-circuit television), the systems were developed in Europe and the USA mainly by enterprises active in televisual R&D. While CCTV today stands as a synonym of the surveillance camera, its historical applications were at least as heterogeneous as contemporary closed-circuits and used on factory floors and in nuclear plants, in hospitals and schools. Operative TV examines two main hypotheses. First, it posits that the analysis of television in industrial, educational, and military contexts cannot be based on habitual analytical categories such as texts or spectators. Instead, AVCC necessitates a methodological shift towards an understanding of audiovisual production as a chain of operations that allows analyzing the entanglement of human and non-human actors. AVCC’s usefulness indeed was contingent on the interplay of heterogeneous elements including operators, screens, infrastructures, and images: their interdependence, rather than the isolated components, should form the core of a historical enquiry. Second, Operative TV argues that the history of AVCC, an analog-electronic technology, nourishes a media archaeology of the digital. AVCC emerged at the same moment as digital computers; it coexisted and sometimes converged with digital machines. Before the computer definitively took over factory and office floors, television was used as a tool for operations ranging from targeting to instructing: analyzing AVCC’s alleged “universality” (Journal d’Yverdon 1955) allows to better understand the emergence of our digital society.