Abstract: A pin table for supporting a workpiece, such as a printed circuit board, while an operation is carried out on it, comprises a base defining a plurality of vertically disposed pneumatic cylinders arranged in a column and row matrix. Each cylinder has a two-position spool valve located axially beneath it in the base for controlling actuation of the cylinder between a position in which the piston rod is fully retracted and a position in which the piston rod is fully raised. The piston rods constitute the pins of the pin table and are selectively movable into their raised positions by the application of compressed air to the cylinders via the spool valves whereby a desired array of raised piston rods may be established.