Figure 1 shows our IBM 557 Alphabetic Interpreter. It is essentially a card printer. The information to be printed, however, comes from the same card that is being printed, and the plugboard control can perform reformatting of the data to be printed. This process requires a lot of complicated machinery. Figure 2 shows part of the card path mechanics. Card are read at the top and part of the 60 individual print bars is seen at the very bottom. The 557 was first introduced in 1954 and is the next-to-last of a line of IBM card interpreters.
An example application of the 557 is printing payroll checks on card stock. Another of IBM's card machines (or even a computer) would punch the information on cards, which would then be run through a 557 to print the readable information such as recipient and amount.