Abstract: A computer output printer is provided with a communications interface having a plurlaity of input ports. Each port can be configured to emulate a different manufacturer's printer, and is provided with a buffer to store print messages while print messages from another port are being printed.

Abstract: A computer output printer includes a host computer interface that enables the printer to emulate a color pen plotter. Pen select commands are interpreted to select a halftone dot pattern, and plot commands are interpreted to define an outline of the line to be plotted, and fill the outline with the selected halftone dot pattern.

Abstract: An electrophotographic reproduction apparatus and method are provided for reproducing an original document sheet that includes a continuous tone pictorial information area and a line-type information area. Rather than reproducing the entire document sheet with screening of both types of information, means are provided for selectively screening only the pictorial information area on the reproduction. The means of one preferred embodiment comprises a programmable illumination source that is programmed through inputs by the operator using a digitizing tablet to selectively image portions of a screen onto a charged photoconductive web prior to development of the electrostatic image formed on the web so that only the area on the web receiving the pictorial image is exposed to the screen.