Abstract: The sheet feeder is formed by a separate unit (10) which can be easily mounted spaced from the platen roller (14) on a typewriter (12) or printer of a data processing system. The print carriers comprise either a continuous web (22) or individual sheets (20). The continuous web is advanced by pin wheels (72) and guided towards the platen roller. The individual sheets (20) which are supported on a feed tray (30) are fed one at a time by means of stripper rollers (40) and passed towards the platen roller (14). The printed sheets are passed into a collector tray (60) by means of collector rollers (54, 56). The pin wheels (72) device and the stripper rollers (40) are rotated selectively from the platen roller by way of a mechanical transmission including a clutch which is actuated by a manual control (116) to connect the pin wheels (72) or the stripper rollers (40) alternatively to the platen roller (14). The manual control also moves the paper guide (52) away from the platen for continuous form feed.