Electronic horizontal shifting and variable print width in a buffered

Abstract

In a buffered printer in which lines of graphic code bytes representing characters to be printed are successively advanced to a line buffer where they are sequentially sampled and the results used to modulate a laser beam undergoing successive scans of a printable medium to effect printing of the characters, an arrangement is provided for determining the size of the lefthand margin of the printable medium and the location adjacent the right-hand edge of the printable medium where printing is to be terminated. The arrangement sums count values representing a fixed offset adjacent the left edge of the printable medium and the distance between the end of the fixed offset and the horizontal location of the desired margin as determined by plural panel mounted switches to provide a first count which is carried out beginning with the start of each scan of the laser beam. Upon termination of the first count, sampling of the graphic code bytes and modulation of the laser beam are initiated simultaneously with the beginning of a second count representing the width of the printable medium minus the count value from the panel mounted switches. Upon completion of the second count, sampling of the graphic code bytes and modulation of the laser beam are terminated until the next scan is begun.