Abstract: Disclosed herein is a method of printing a document image with a host computer and an associated printer, where the printer has a printhead with a plurality of laterally-spaced dot columns. The method includes rasterizing the document image in the host computer to produce raster-formatted data representing the document image. This data is then segregated into data swaths corresponding to swaths of the printhead, and further segregating into dot-column data blocks corresponding to printhead dot columns. The dot-column data blocks are then sent to the printer in the order in which they will be processed by printhead electronics within the printer. The printer passes the dot-column data blocks to the printhead to control firing of printhead's nozzles.

Abstract: A printer controller employs a microprocessor together with an application-specific-integrated-circuit (ASIC) to manage the operation of the printer. Among its functions, the ASIC manages memory access for the microprocessor. Either fast- or slow-clock microprocessors may be installed in the controller, but the ASIC requires a slow clock. When a fast-clock microprocessor is installed, the ASIC must divide the clock frequency to provide its own (slow) clock. Likewise, the use of a fast-clock microprocessor requires the ASIC to insert memory-cycle WAIT times, whereas a slow-clock microprocessor needs no WAITs. In a preferred embodiment of the invention, provision is made, during initial power-on RESET, to inform the ASIC which clock speed is being used. This information is conveyed by the configuration of the WAIT interconnection between ASIC and microprocessor, thus eliminating the need for a dedicated ASIC pin for this purpose.