A control system for operating a hydraulic system (10) includes a user input device (47) which generates an input signal indicating desired movement of a hydraulic actuator (16). A mapping routine (50) converts the input signal into a velocity command indicating a desired actuator velocity. A valve opening routine (56) transforms the velocity command into a flow coefficient which characterizes fluid flow through the valve assembly (25) and from the flow coefficient produces a set of control signals designating levels of electric current to apply to valves (21-24) within the valve assembly. A pressure controller (64) regulates pressure in the supply line (14) in response to the velocity command. When the hydraulic system (10) has a plurality of functions (11,20), the control system adjusts each velocity command to equitably apportion fluid to each function, when the aggregate flow being demanded by the functions exceeds the total flow available from a source.