Abstract: A controller section registers a character pattern and individual information thereof in a buffer memory. The individual information includes a first flag indicating a first processing state and a character code assigned to the character pattern. The controller detects the individual information of a character pattern previously stored in the buffer memory. Further, the controller section stores a new character pattern by overwriting the previously-stored character pattern according to the detected individual information of the previously-stored character pattern.

Abstract: A printer using an external font cartridge, includes a printer main body and a cartridge. The printer main body includes an internal font data memory, a program memory, a control section, and a printing mechanical section. The internal font data memory stores internal font data. The program memory stores at least an internal font development program. The control section performs control to generate print data on the basis of the internal font data and the internal font development program. The printing mechanical section prints the print data generated by the control section. The cartridge includes an external font data memory and an external font development program memory. The external font data memory stores external font data. The external font development program memory stores an external font development program.