Abstract: Apparatus and methods for adjusting a skew angle of an LED array in the second of dual/tandem print engine systems to compensate for shrinkage of the printable medium exiting the first print engine. Features and aspects hereof provide for manually and/or automatically measuring the shrinkage of the printable medium as it exits the first print engine and for automatically and/or manually adjusting the skew angle of the mounting of the LED array in the second print engine. The image data applied through the LED to the corresponding photoconductor of the second print engine is similarly skewed to match the skew angle of the LED array. Thus a substantially normal bitmap image is applied through the skewed LED to the photoconductor of the second print engine shrunk in the width dimension. Visual artifacts and anomalies from the mathematical approximations and rounding are visually imperceptible at sufficiently high resolutions.

Abstract: Provided are a method, system, and article of manufacture for using operation codes to control a decoder's use of a buffer to generate data from an input data stream into an output data stream. An encoder generates an input data stream for a decoder comprising at least one operation code and compressed data for an output device. The at least one operation code instructs the decoder on how to use a buffer when processing the input data stream. The decoder receives the input data stream, processes the data in the input data stream to perform an operation with respect to the buffer according to the at least one operation code, and decodes the compressed data into decompressed data to send to an output data stream to the output device.

Abstract: Apparatus and methods for adjusting a skew angle of an LED array in the second of dual/tandem print engine systems to compensate for shrinkage of the printable medium exiting the first print engine. Features and aspects hereof provide for manually and/or automatically measuring the shrinkage of the printable medium as it exits the first print engine and for automatically and/or manually adjusting the skew angle of the mounting of the LED array in the second print engine. The image data applied through the LED to the corresponding photoconductor of the second print engine is similarly skewed to match the skew angle of the LED array. Thus a substantially normal bitmap image is applied through the skewed LED to the photoconductor of the second print engine shrunk in the width dimension. Visual artifacts and anomalies from the mathematical approximations and rounding are visually imperceptible at sufficiently high resolutions.

Abstract: Provided are a method, system, and article of manufacture for using operation codes to control a decoder to generate data from an input data stream into an output data stream. An encoder generates an input data stream for a decoder comprising at least one operation code and compressed data for an output device. The at least one operation code instructs the decoder on how to process the compressed data. The decoder receives the input data stream and processes the data in the input data stream according to the at least one operation code. The decoder decodes the compressed data into decompressed data to send to an output data stream to the output device.

Abstract: Provided are a method, system, and article of manufacture for using operation codes to control a decoder's use of a buffer to generate data from an input data stream into an output data stream. An encoder generates an input data stream for a decoder comprising at least one operation code and compressed data for an output device. The at least one operation code instructs the decoder on how to use a buffer when processing the input data stream. The decoder receives the input data stream, processes the data in the input data stream to perform an operation with respect to the buffer according to the at least one operation code, and decodes the compressed data into decompressed data to send to an output data stream to the output device.

Abstract: A system, apparatus, method and program for controlling and tracking printable object headers associated with print objects being processed for printing in a printing system. The print object headers are provided in a plurality of queues, which are serially arranged in a stacked queue configuration. Print object headers are received at a first one of the queues, and as additional print object headers enter the stacked object queue via the first queue, they are controllably shifted through the remaining queues as they become available.

Abstract: A method and apparatus for error checking in a digital scanning device. An error detection pattern is written into each of a plurality of parallel data streams. Each of the data streams is then transmitted through a separate parallel data channel. The error detection patterns in the data streams are then concurrently compared to one another to check for an error condition of the data stream. If the error detection patterns are not received substantially concurrently, an error condition is considered to have occurred. The error detection pattern may comprise end of scan, end of sheet or First-In First-Out (FIFO) buffer data. While all error conditions are false, printing and data transmission continue. Printing and data transmission are terminated if any error condition is true, and an error notification message is generated.

Abstract: An output interface allows a user circuit to access data for multiple objects in an interleaved fashion. Status information is provided to guarantee data availability before each transfer sequence is started. An identifier is provided for each object. Each identifier, after data transfer has ended, may be subsequently reused to identify a different object. The interface provides the ability to retrieve all data in an object or to cancel the object before reaching the end and discarding the unretrieved data. The objects are provided to the appropriate processing mechanisms within the printer to implement a printing task. These objects correspond to images and text to be printed on a page. Object data is temporarily stored in limited data memory of the memory system and object headers are stored in header memory before transfer via the output interface. Each object to be printed has an object header and may, or may not, have associated object data.

Abstract: An integrated circuit device or chip enables a system interface to read multiple design level/version numbers of multiple and independent version numbers per chip to identify independently modifiable sub-sections of the chip (or module) design. The design enables one to store both creation and modification dates and/or version numbers for each sub-section or partition of the chip design, referred to herein generally as functional units. The values can be hard-coded into the design, such as in the case of an ASIC, or they can be placed in a FPGA download design and stored as part of the FPGA configuration procedure. The values can also be stored from the input pins of the integrated circuit. The readout of the version information can be performed via a hardware trace register readout through a system interface. In this manner one is enabled to implement multiple level control to separate the functional and diagnostic area of the chip.

Abstract: A reduction in the number of cycles required to obtain data from main storage when a "miss" occurs in a cache for a desired line of data but a match to another line from the same page of data in main storage as the desired line is present in the cache. In accordance with the present invention if a match to another line from the same page is present, the real address for the other line from the same page is used to fetch the desired line of data directly from the main storage without an address translation. This technique works for a virtually addressed cache whose directory contains both a virtual and a real address for every line of data stored in the cache.