A system is disclosed that includes a selectively positionable brake for a towed fishing body. The system software includes instructions for operating the telephone system, and requires license information to operate. A keyboard tray is engageable with the left and right mouse trays to prevent lateral movement of the keyboard tray, but allows the keyboard tray to be lifted up from engagement with both mouse trays and moved out of the entryexit position of the chair so that the user can have access to the chair. The metering pump delivers the material to the nozzle at controlled volumetric rates that correspond to the controlled speeds of relative motion between the nozzle and the sash. Normal and automatic modes for the precharge control are available, with the automatic mode eliminating the need for the precharge enable register location being written during operation.