The search for a satisfactory computer graphics input system led to this version of an analog sheet encoder which is transparent and requires no special probes. The goal of the research was to provide high resolution touch input capabilities for an experimental minicomputer based intelligent terminal system. The technique explored is compatible with AC plasma display technology, and the work reported demonstrates an analog realization for graphic input that is both feasible and economically attractive. Use of the encoder can result in large amounts of raw data, but the local terminal processor and storage give the programer a high degree of flexibility for data management. (WBC)