PURPOSE: To enable the status of progress in printing to be confirmed by calculating the number of pages of received printing data and the number of pages of output printing data.

CONSTITUTION: A single data is read from among those transmitted from a host computer 1 and then is stored in a page buffer (a) of a page buffer 24. If data that is read is a page feed code, a value 1 is added to a page counter 22. The number of pages obtained in this way is output to a printer display section 25. Next, if single data is read from the page buffer (a) for pattern development, and a page feed code is detected, a dot printer 27 is started to start printing of a pattern developed on a frame buffer 26. After this, a value 1 is subtracted from a page counter and this number of pages is output to the display 25. By the processing described above, the number of pages of data waiting for printing can be displayed.