What is the difference between Type I, Type II, and Type III PC Cards?
Type I - First standard defined by PC Card Association. Dimensions: 85.6 mm x 54.0 mm x 3.3 mm.
Type II - Second standard form factor defined by PC Card Association. Dimensions: 85.6 mm x 54.0 mm x 5.0 mm. The KODAK Picture Card with Adapter fit into a Type II slot.
Type III - Third standard form factor defined by PC Card Association. Dimensions: 85.6 mm x 54.0 mm x 10.5 mm. An example of this is the PCMCIA hard drive in a KODAK PROFESSIONAL DCS Digital Camera.
One of the differences is physical size. A Type I card fits into a Type II slot. A Type I and Type II cards fit into a Type III slot. Due to the larger physical size, the Type III card does not fit into a Type II or Type I slot. Similarly, a Type II card does not fit into a Type I slot.