Abstract: A dot matrix impact printer includes a retractable platen which positions an elongated sheet of paper in a location where a print head prints a line of data on the paper. In a second mode of operation, the insertion of a form, shorter than the elongated sheet of paper, is detected by photodetecting means. The form is inserted in overlying relation to the elongated sheet, where it is juxtaposed against the retractable platen. The photodetecting means in turn activate a solenoid. Activation of the solenoid displaces relatively small rollers against the inserted form in a manner pressing the form against the elongated sheet of paper. An intermediate length of the sheet is supported by a relatively large roller which undergoes indexed movement. As the sheet undergoes indexed movement during a printing operation, so does the form. At the end of a printing operation, the solenoid automatically retracts the relatively small rollers thereby permitting the withdrawal of the form.