Abstract: A means for presenting individual instructions from a group of predetermined instructions in a random fashion is provided by a random word generator and a binary counter which cooperate to address a programmable read-only memory which sequentially provides character forming potentials to a plurality of fluorescent character display indicators so that each indicator receives the same character forming potentials at each step in the sequence in combination with a binary decoder responsive to the binary counter for enabling only one of the indicators for each step in the sequence.