Abstract: An improved high speed impact matrix printer is provided for use with data processing systems and digital communication systems. In the serial wire matrix printer (10) of the preferred embodiment, a printhead (36) has print wires (90) arranged as a column within a wire guide (88). The printhead (36) is stepped serially across a print record, and print wire drivers (68) fire the print wires (90) in accordance with character configuration information in storage to effect the printing of a line of characters. The impact head of each print wire (90) is elongated with its longitudinal dimensions extending in the direction of relative movement of the printhead (36) along the print line. The elongated impact head of the print wire (90) extends over a plurality of print firing locations of a matrix character pattern to reduce the number of times the print wire drivers (68) must fire the print wires (90) to print a character.

Abstract: An information transfer system is described that includes a central processing unit (CPU) interconnected with a peripheral device such as an operator console by an interface bus of finite capacity. Transfer of information in the system is normally in a preferred direction from the CPU to the console. Provision is made to transfer information concerning key depressions on the console from the console to the CPU without using the bus by utilizing a normally continuously operating counter in the CPU that provides a sequence of coded count signals representative of individual keys that are provided on the console and that may be depressed. A comparator in the console compares coded count signals from the CPU counter with coded signals from the console representative of actual key depressions and provides a stop signal to the CPU counter via a single control line when an equal compare of the CPU counter and console coded signals occurs.

Abstract: A method and apparatus is shown for improving the clarity and character density on a cathode ray tube (CRT) display in which characters are formed row by row from discrete character elements in row and column coordinate matrices. Unblanking signals form the discrete character elements no less than two matrix spaces wide every time an unblanking signal is applied. This technique results in a much crisper appearance to the characters on the screen and permits as many as 128 characters per line using a low cost commercially available television (TV) monitor. A random access storage is used to store dynamically the addresses of positions (locations) of a read only store corresponding to characters to be displayed. The read only store (ROS) contains indicia corresponding to the discrete character elements of a plurality of characters, one set of indicia for each character in the desired character set.