A slide rack determination system for a digital slide scanning apparatus. In an embodiment, a motor drives a slide rack at a known rate toward an engagement surface. The elapsed time until engagement may be used to detect the presence or absence of the slide rack and/or the height of the slide rack. In addition, one or more sensors may detect one or more features of the slide rack, and these feature(s) may be used to determine the presence or absence of a slide rack, whether usage of the slide rack is supported or unsupported by the digital slide scanning apparatus, the orientation of the slide rack, and/or the manufacturer and/or model of the slide rack.