[en] A portable remote-handling system (Monitor) has been developed for remote maintenance of the extremely radioactive main experimental beam line at the Clinton P. Anderson Meson Physics Facility (LAMPF). The system has been in a constant state of development since 1976 and has served a vital role in the success of LAMPF's experimental program. The history of the development of the overall monitor system was presented in previous papers. This paper will specifically address the development of the control system and the factors, human and otherwise, that led to the present design. The control system layout started as two instrument racks. It has progressed to a sophisticated control room housed in a dedicated trailer. The control system development has kept pace with the overall system development to perform the sophisticated maintenance, repair, and replacement of the main experimental beam line at LAMPF