TITLE
    LaserWriter Select 360: Automatic Emulation Switching (8/94)
Article ID:
Created:
Modified:
13710
10/19/93
8/23/94

TOPIC



    This article discusses the automatic emulation switching technology
    incorporated into the LaserWriter Select 360.


DISCUSSION


    The LaserWriter Select 360 has the ability to sense an interface port
    data stream to determine the start and end of PostScript print jobs,
    PCL 5 print jobs, PC DOS PrtScn dumps, Hewlett Packard TBCP (Tagged
    Binary) and raw text dumps. This function is the key to providing
    simultaneously active ports and seamless switching between PCL 5,
    PostScript, and raw text printing.

    Each interface port has the ability to process either a single
    emulation or multiple emulations. If an interface port is assigned
    multiple emulation responsibilities, all data sent to it is processed
    by the data sensing function. Ports configured for single emulation
    responsibility have the data sent directly to the assigned emulation
    processor.

    Fonts that are downloaded for specific jobs remain in memory for the
    PostScript environment and the PCL 5 environment. If the active
    environment (either PostScript or PCL 5) runs out of virtual memory,
    inactive downloaded fonts are released as needed to regain enough
    memory to perform the current job.

    The success of automatic emulation switching is tied to the correct
    usage of the Hewlett-Packard Printer Job Language, the use of PCL 5
    print job delimiters, and proper implementations of the Adobe Document
    Structuring Conventions. Job streams that do not abide by the
    protocols produce print data that can't be properly sensed and
    processed.

    Article Change History:
    23 Aug 1994 - Review for accuracy.

    Support Information Services



Document Information
Product Area: Printers
Category: LaserWriters
Sub Category: LaserWriter Select 360

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