Abstract: A printing system includes a plurality of print engines; a raster printer controller having a processor for generating the rasterized bitmap data; and a plurality of print engine communication devices, where each of the print engine communication devices are coupled to a corresponding one of the print engines to provide the rasterized bitmap data to the corresponding print engine. The print engine communication devices are coupled together with the raster printer controller in a daisy chain configuration by a data link. Each of the print engine communication devices includes a message processing circuit that is adapted to monitor data received from raster printer controller, execute commands embedded in data received, update a bitmap data memory storage buffer in the print engine communication device with rasterized bitmap data embedded in the data received from the raster printer controller.

Abstract: A digital high-speed printing system architecture for processing contiguous raster-image data blocks for transmission to a marking engine, comprises a central processing unit ("CPU") and at least one video RAM device. Each video RAM device includes a dynamic band RAM, a serial access memory, a random access port for transmitting and receiving image data blocks to and from the dynamic band RAM, and a serial port for transmitting and receiving image data blocks to and from the serial access memory. The video RAM devices perform bi-directional image data block transfers between the dynamic band RAM and the serial access memory. Furthermore, the video RAM devices transfer image data blocks to and from the serial access port, and simultaneously transfer of image data blocks to and from the random access port.

Abstract: An on-board diagnostic system which comprises dedicated hardware for performing run-time diagnostics on a computer board having several functional sections. The diagnostic system utilizes a serial token ring network, which preferably has a software-independent, hardware core, comprising a non-intelligent master device and a plurality of non-intelligent slave devices. The master and slave devices are all interconnected via a dedicated serial data bus which operates independently of the on-board CPUs and on-board CPU buses. Each slave device is responsible for monitoring a particular section of the computer board. The master device polls each slave device by activating a corresponding token line on each slave device for a predetermined period of time, one at a time, until the master device is alerted by a slave device that a change of state has occurred in the status signals of that particular section.

Abstract: An electronic image registration method for use with a high-speed raster printer controller provides run-time registration of an image which is defined by a continuous stream of rasterized bit-map data. The method includes the steps of: (a) detecting a misalignment of the image with respect to a form, and producing a registration value in response to the detected misalignment; (b) acquiring a present block of the bit-map data from the stream; (c) shifting the present block of the bit-map data a number of bits according to a shift count generated from the registration value produced in step (a) to create a present contiguous set of shifted bit-map data bits and a present contiguous set of spill-over bit-map data bits; (d) storing the present set of spill-over bits; (e) combining the present set of shifted bits with a previous contiguous set of spill-over bit-map data bits to create a present registered block of bit-map data; and (e) dispatching the present registered block to a print engine.

Abstract: A method and architecture is provided for merging a variable image data bitmap into a template image and for transmitting the merged image to a print engine; where the template image is defined by rendering commands derived from a page description language, and the variable image data bitmap is taken from a list of the variable data bitmaps. The method comprises the steps of continuously rendering template image data bands, in accordance with the set of rendering commands, and transferring the template image data bands to a mass storage. Once the entire template image is stored in the mass storage, the variable image data bitmap is merged with the template image bitmap and sent to the print engine by continuously loading template image data bands from the mass storage, logically mapping the variable image data bitmap into the template image data bands to produce merged image data bands, and dispatching the merged image data bands to the print engine.

Abstract: A method for printing variable data with a page description language, which enables the graphics states for a page of variable data to be defined and stored; and which enables the stored graphics states to be associated with items of variable data from a database, so that once defined, the graphics states can be used to print multiple pages of variable data. The method of the present invention is implemented by means of a control task, which executes in a printer in conjunction with a page description program, to identify variable data areas in the program, and store the graphics states for the variable data areas as they are defined by the program. After the program has terminated, a merge task associates items of variable data from a data file with the graphics states, generates a bit map for each variable data area, merges the bit maps with the page template, and outputs the page from the printer.

Abstract: A printer controller system for converting a page description language datastream into a pagemap and for dispatching the pagemap to a print engine one band at a time. The system includes the steps of interpreting the PDL datastream to generate a plurality of rendering commands; partitioning the page into a plurality of bands; allocating memory for at least one of the bands; rendering a bitmap in the allocated memory by processing the rendering commands; monitoring access to the allocated memory while processing a rendering command; saving off the rendering command if the processing operation attempts to access memory outside of the allocated memory; and dispatching the bitmap to a print engine. The saved off rendering commands will be retrieved and processing of them will be resumed when rendering the bitmap of the next band. Preferably, the tasks of interpreting the PDL datastream, rendering the bitmaps of the bands, and dispatching the rendered bands, are performed in parallel by separate processing units.