A cylinder with a continuously variable piston area is considered by many an impossible goal. This paper presents solutions for digital hydraulic cylinders with certain discrete values of multiple surfaces, which, selected by well established rules, can control the force and speed output values although they are supplied with constant pressure and flow. Also hereinafter we present test diagrams for digital pumps and digital switching directional control valves, as well as a test stand model for multiple-area cylinders, their testing methodology and mathematical modeling of a three-area digital cylinder.