March 22, 2017
The 1403 family was IBM's flagship line of printers in the 1960s, supporting the permanent record needs of the 1401 system at 600 lines per minute, and the System/360 at 1,100 lines per minute. The System/360 high speed printer was known internally as the 1403-N1.
The printer is an electro-mechanical unit. Controls for the 1403 family of printers were provided by circuitry within the data processing system, not the printer. A plethora of printer controllers were tailored for each of the CPU-Printer combinations. With the advent of the System/360, the CPU interface was standardized and the 1403-N1’s printer controller moved to a separate unit, the IBM 2821. It used IBM's first generation printed circuitry — Standard Modular System (SMS) cards, which consisted of discrete transistors, resistors, capacitors, and other components mounted on single layer printed circuit boards. Circuit cards controlled the timing of pulses that energized the printer hammers for about 1.2 milliseconds in duration, a critical parameter for high quality printing. The 2821 also contained power supplies to drive the hammers, buffers to hold the print data, and additional electronics to interface to the host computer.