PRINTER

PURPOSE:To achieve reduction of labor in operations and costs by promoting interchangeability of a printer, by a method wherein a printing process of printing data is performed on a controlling program supplied from an information processor. CONSTITUTION:A CPU 4 judges whether information from a host computer 2 is a controlling program or a printing data. For the controlling program, it is stored in a program memory 5, and various processing are executed on the program. Further, when the printing data is sent after storing the controlling program in the program memory 5, the CPU 4 supplies this data to the program memory 5 side successively accumulating this data to a buffer input data 6 side, executes interpretation of the printing data and preparation of an image data based on the controlling program, and supplies this image data to a buffer for output image 7. Further, printing processing of the image data is performed by controlling a printer 8. Therefore, even when the host computer 2 is replaced by other type of computers, conforming operation is executed on said controlling program, and high interchangeability can be obtained.