typical system consists of a mainframe minicomputer, disk and magnetic tape units, station interface hardware, graphics software. graphics work stations, and a plotter. Other optional peripherals such as line printers, hard-copy units, alphanumeric terminals, and on-line stereoplotters may also be a part of the system. Acquisition of the interactive graphics capability may occur in one of a number of ways, from the complete development of the entire hardware/software components to the purchase of a “turnkey” hardware/software system to the purchase of the capability as a service. The advantages and disadvantages of the possible approaches are presented in Table 3.7 (Dangermond and Smith, 1980).