A page printer which rasterizes a page utilizing partial page bit map swaths. Received data to be printed is stored in packets (12-17) in a page buffer in random access memory. Data within each packet is arranged in printing order down the page to be printed, but the pack­ets themselves are arranged in the order received, and are not indexed or linked. As each swath (11) is rasterized, each packet is examined, and packets containing data falling at least in part within the active swath are processed. The printer is controlled by a programmed microprocessor, and logic hardware assistance is provided for translating data addresses from logical addresses to physical addresses. Logic hardware assistance is also provided for making the determination of whether or not a given data address lies within the active swath.