Editing Atari 1027 (section)

=== Mechanism ===

A DC motor turns the type wheel shaft through an idle gear. When the wanted character faces the hammer, solenoid A (character select) stops the wheel. A wheel select stepper moves the wheel along its shaft by a wire and pulley, and a hammer stepper moves the hammer to match; a cam on the type wheel shaft then fires the hammer and, when a blank is selected, advances the paper through a rubber roller. Photosensors read each character position, the type wheel home position and the hammer home position. The ink roller snaps onto a post in front of the type wheel.<ref name="fsm" />