Unimation PUMA Teach Pendant / VAL

The teach pendant's deepest idea was that an assembly robot would be programmed by a human's hands, not a compiler. In teach mode you steered the arm to a position — jog toggles for coarse motion, the INC setting for servo-resolution increments — and pressed RECORD to save the point. FREE mode went further: it let the operator physically push the arm through a motion while the controller captured the path. This is programming-by-manipulation, the ancestor of today's kinesthetic teaching in collaborative robotics, and it made the boundary between human and machine physical — the OFF panic button, and a philosophy in which the robot is never autonomous while a person shares its space.

The manual control unit was a heavy handheld box tethered to the controller. Mode switches ran along the edge, the speed control doubled as an increment dial, and the joint toggles had to be held, so every programmed move was deliberate. The display reported teach mode, errors, and calibration status, and the pendant's commands mapped onto VAL instructions the operator never typed. Later pendants added the three-position dead-man/enabling switch that became an industry safety standard — a direct descendant of the PUMA pendant's hold-to-operate logic.

VAL bridged pendant and program, combining a motion command language ('MOVE TO PART', 'APPRO', 'DEPART') with an editor and executor. MIT's AI Lab famously ran a PUMA 600 from a Lisp Machine via VAL in 1982 ('Talking to the Puma'). Its significance for HCI is that the program was written in the machine's own joint and world coordinates, captured from the human's gestures rather than from text — the teach-pendant-plus-script pattern that still defines how industrial robots are configured today.