XCRIBL: A Hardcopy Scan Line Graphics System for Document Generation

摘要

XCRIBL is a system developed at CMU for generating hard copy computer output of arbitrary type fonts, graphics, and grey-scale images using a Xerox Graphic Printer (XGP). XCRIBL can be used to generate documents approaching the quality of printed text with the use of a document generation language (XOFF or PUB) and a character set design program (BILOS). Textual and graphic information to be printed is shipped in its raw form from the host computer (PDP-10) to a mini-computer (PDP-11) which acts as an intelligent channel controlling the XGP. Careful design of the data structures and the hardware interface permit the mini-computer to generate each scan line as needed without having to resort to a brute force solution of generating a bit-image for the whole page (3.5 million bits) for off-line printing. Variable width characters and the ability to mix text and graphics distinguish the present solution from the known simpler schemes for scan line generation. (Author)