Abstract: The present invention is directed to a printer and comprises a printing mechanism, a paper guiding path connecting with the printing mechanism, a driving source for a paper conveying system, an output gear connected to an output shaft of the driving source, and a permanent tractor having an input gear. The selective transmission of power from the driving source to either the output gear or the input gear provided in the permanent tractor is performed by a power selecting mechanism operated by an operating member. Further, the printer comprises a second drive force selecting mechanism for independently displacing a cam member in the printer and a clutch section for severing the connection between the output gear and the auxiliary tractor in order to feed only the cut paper.