The VHF system used by the Satellite Technology Demonstration had a built-in digital response system to collect data about student programing. This paper describes the hardware and software required to implement and operate the system. In addition, information on the applications of this device is provided along with the results of a field experiment in which junior high school students used the system. A general description of the VHF is presented as a necessary background for the description of the limited digital response. The details of the data collection also are presented. Finally, the applications and results of the system are given. (Author/EMH)