Abstract: An improved control unit is provided in the form of a compact and relatively simple add-on kit for use with calculators, adding machines and the like requiring use of paper tape in roll form. The paper tape control unit supplies the paper tape to the associated machine and rewinds that tape in a continuously controlled manner while permitting relatively easy periodic reversal of tape motion for review purposes. The control unit includes supply and take-up reels driven together by a drive belt adapted for sufficient slipping motion to accommodate diametric size changes in the reels as the tape is unwound and wound with respect thereto. An adjustable platen is supported by the control unit in a position for passage of imprinted tape thereover to facilitate placement of manual edits or notations prior to winding of the tape onto the take-up reel.