IBM 552 Alphabetical Interpreter

An interpreter adds printing to punched but otherwise blank cards, based on what's punched on each card. Most were not capable of reading or interpreting all 80 columns of a card. Thus the desired fields had to be selected by wiring the control panel appropriately. In any case, the printing characters were wider than the card columns, and did not line up. The 551 and 552 models, by allowing more than one row to be printed, also allowed interpretation of all 80 card columns by running the cards through twice with different column and row selections. The 551 requires one pass for each of up to 5 rows that is to be printed. The printing row is selected by a knob, shown below. On the 557, up to 25 rows can be printed in a signle pass. The print mechanism is a type bar; this is not dot-matrix printing as on the key punch, which differs from the printing on interpreted cards with its 1-to-1 correspondence with the card columns.