Abstract: A method and system is provided for partial job interrupt of an on-going first print job to cause a contemporaneous parallel printing of a second print job. A plurality of marking engines associated with the storage device for receiving and storing a plurality of print jobs in queue, executes a first print job and outputs the sheets to an assigned first sheet output. A user determines that a second print job sent to the system and stored in the queue behind the first print job will be undesirably delayed and so interrupts the first print job by limiting the executing of the first print job to less than all of the plurality of print engines within the printing system. An output of the first print job is maintained at the first job sheet output. The second print job can then be contemporaneously executed with the execution of the first print job with available print engines interrupted from the first print job.

Abstract: In a dual engine printing system producing a multipage print job from first and second serially connected printing engines at a common output from the second engine, where the second printing engine has a duplex return path bypassing its printing path and extending substantially therethrough, a high productivity simplex job printing mode is provided in which alternate pages are substantially simultaneously printed in both the first and second printing engines, but the alternate pages printed in the first printing engine are fed to the second printing engine duplex return path to bypass the printing path of the second printing engine and then are automatically interleaved in the common output with the alternate pages printed in the second printing engine. The duplex return path is preferably a bidirectional loop extending above the printing path and driven in a reverse sheet feeding direction for this simplex printing.