Reconfigurable printer

摘要

A printer having a number of optional features or operations is reconfigurable by software alone. The printer includes an EPROM that stores the software routines defining all of the optional operations of the printer. An EEPROM stores a jump table identifying each optional operation software routine as enabled or disabled. The information stored in the jump table for each enabled routine identifies the location at which the routine is stored in the EPROM; whereas, the information stored for each disabled routine includes a disable flag. The printer includes an interface which allows a new jump table to be downloaded from a personal computer into the EEPROM of the printer to enable disabled routines, to disable enabled routines, and to replace disabled routines by downloading a new routine into a RAM to thereby reconfigure the printer. A master jump table and sub-jump tables are provided to increase the efficiency of the reconfiguring operation. Further, several checks are implemented by the printer and the personal computer during the reconfiguration operation to insure that only the correct printer is reconfigured and that information is stored at the proper location in the printer.