Abstract: A Thin Layer Protocol.TM. adds three new data stream commands--the WOCC, WOC and END commands--to the Intelligent Printer Data Stream.TM. ("IPDS.TM.") structured page description language. The WOCC command creates a container for encapsulating a foreign print object, such as a PostScript.TM. or PCL.TM. command stream The container includes information identifying the type of object it contains. The WOC command provides the foreign print object data for the container and includes information defining the length of the object. The END command unambiguously locates the end of the container to prevent confusion of encapsulated binary data with escape sequences. Long objects are partitioned using separate WOC commands, each providing the length of its partition. The object type information enables the printer to easily invoke an appropriate language interpreter. Alternatively, the printer may use the object type and object length information to skip over an object which it does not recognize.

Abstract: A computer-controlled printing system includes a host computer, an intelligent printer and an intelligent post printer processor. The print job is controlled by defining print data, printer control data and printer post processor control data in a print data stream from the host computer. The print data and printer control data are read at the intelligent printer. The intelligent printer executes the print control data to print the print data on a print medium. The printer also determines if there is post processor control data in the print data stream and, if so, sends the post processor control data from the printer to the intelligent post processor. The post processor reads the post processor control data, and executes the post processor control data to perform selected modification of the print medium.