Download of interpreter to a printer

摘要

Printer (1) has code in memory (5) to interpret one or more page description languages and also stores in memory (5) a table of routines useful in other interpreters and their addresses, as well as code to link partially compiled object code in response to directions in Relocation Tables in the partially compiled code. Data is downloaded to the printer by cable (23) to add another interpreter to the printer. That data is employed by the linking code, which responds to the directions in the Relocation Tables to complete the new interpreter making use of routines already stored in the printer. Since the stored routine table is lengthy, it is compressed. The routine table may be downloaded rather than permanently stored. <IMAGE>