Abstract: A computer mouse having a roller which implements a scrolling function for computer programs, particularly those running a windows format. In one embodiment, scrolling is implemented by sending messages to a queue associated with a windows kernel. The kernel interprets scrolling messages from the roller in the same manner as messages generated in the usual way from a graphical user interface. Rapid turning of the roller generates pulses which are stored in a buffer and interpreted as energy which is drawn from the buffer even after the roller stops turning so that scrolling continues until stopped or until the buffer is depleted.