Abstract: A system for the interactive control of a display such as a CRT (cathode ray tube) or the like, produces a visual representation of at least one variable in the form of a trend or bar graph. The system includes a personal computer having a cursor control and a display. The system operator can select a variable for display, and then select a location within which the visual representation of the variable is to appear and a range of the variable which is to be displayed within the selected region. The system responds to the operator's selections for producing a visual representation in the form of a trend or bar graph of the selected variable within the selected range at the operator-selected location.