CCTVs, also known as video magnifiers, provide on-the-fly magnification of many types of materials that scanners can't process, including handwritten documents. They can also be used to magnify detailed handiwork, such as sewing or assembling small objects.
Most CCTVs, including the one at the Knox Center, have a bed where the user places the materials to be magnified. This bed can be moved around to change what part of the material is shown on the monitor.
Optelec ClearView+ (stand-alone)