The circuits and programs that conform the prototype of a curve tracer, operated under the control of a personal computer (PC) are presented. The prototype uses a data acquisition board that generates the signals applied to the base and collector terminals of the tracer. This board also carries out the necessary measurements to trace the characteristic curves of the device under test. It was designed an additional board with the appropriate circuit for the base and collector terminals. A program was written in the graphical language G of LabView^TM to program the complete operation of the tracer and to control the external circuits. The developed program presents the results in a graphic indicator as a family of curves, it can store in a file the parameters of the characterization process, and also, the program can open files to plot the information stored.