18. A machine for teaching students to read according to claim 15 further characterized in that said letter combinations are words and further comprising: correctness and incorrectness indicators, and console means having manually actuable switches for generating electronic signals for different grammar characteristics, and further characterized in that said logic processing means is adapted to ascertain the existence of a particular grammar characteristic associated with each word received from said addressed memory block location, to store an encoded indication of said existence in temporary memory storage and to draw said encoded indication from temporary memory storage upon subsequent receipt of an electronic signal from said console means for comparision therebetween, comparator means connected to said logic processing means for receiving said electronic signals from said console means and the most recently stored encoded indication of existence of a particular grammar characteristic and for providing an output indication of comparison results to one of said correctness and incorrectness indicators.
15. A machine for teaching students to read comprising: visual display means for receiving encoded letter combinations to provide visual images thereof as transmitted thereto, storage means having a plurality of memory locations in which sets of letter combinations are separately stored in electronically encoded form, logic processing means to address said memory locations one at a time and to provide to said visual display means encoded letter combinations as said letter combinations are received from said addressed memory locations, word selection means connected to said storage means to randomly select from among the addresses of letter combinations addressed and to sequentially extract letter combinations therefrom and transfer said extracted letter combinations at said selected addresses to said logic processing means for display.