1. AN ALPHA-NUMERIC DISPLAY DEVICE COMPRISING: A MASK WITH A PLURALITY OF PEEPHOLES EXTENDING THERETHROUGH HAVING A SELECTIVE ARRANGEMENT; AND A CYLINDRICAL DISPLAY MEMBER HAVING STEPPED DISPLACEMENTS RELATIVE TO SAID MASK AND HAVING A SURFACE WHICH UNDERLIES SAID PEEPHOLES WITH A PLURALITY OF DOTS MARKED THEREON AND SELECTIVELY ARRANGED IN A SUCCESSION OF GROUPS REPRESENTING ALPHA-NUMERIC CHARACTERS, THE ARRANGEMENT OF WHICH AS SEEN THROUGH THE MASK DISPLAYS ALPHA-NUMERIC SYMBOLS, EACH SYMBOL BEING OF SUCH SIZE AS TO SUBTEND AN ARC OF MORE THAN 36* OF THE CYLINDER, EACH SYMBOL BEING DISPLAYED THROUGH THE MASK IN RESPONSE TO A MOVEMENT OF THE DISPLAY MEMBER A DISTANCE OF LESS THAN ONEHALF THE SIZE OF EACH SYMBOL; WHEREBY ONE NUMERAL AT A TIME IN A SERIES OF SUCCESSIVE NUMERALS IS DISPLAYED IN SAID PEEPHOLES.