Machine-readable symbol reader systems including one or more shields are provided. The image forming apparatus, in a case where a print setting for printing an image on an unprinted surface of a preprinted sheet has been set and a surface of the sheet read by the reading unit is not a preprinted surface, executes printing on the sheet. An adjustment to an emotional attribute of a game character is determined based on an interaction with another game character. A hold-down feature is mounted on the base adjacent to the cradle in a substantially stationary position relative to the cradle movement. The oscillator produces an oscillating output with a frequency of oscillation dependent on the pulse generator current, and the counter provides an oscillation count for the oscillating output.