To improve the learning process, a better "impedance" match to the beginning ECE student was sought at the University of Tennessee, Knoxville (UTK). To do this, a personal computer interfaced to an analog-to-digital (A/D) interface and was envisioned. Commercially available A/D-D/A computer interface devices were reviewed for suitability and, although they would provide attractive features, they were outside our budget. Based on experience in the student labs, an affordable virtual scope combination of hardware and software was conceived that would aid the beginning ECE student. It seems to come close to the ideal instrument for the student to use in the lab because the instrument functions are transparent, e.g., it does not have so many of the knobs that often get in the way of the measurement process. The functions are also simple and obvious to the student. An early concern was that such a simple approach might only postpone the necessary mastery of the modern oscilloscope by the student. However, in actual use by students in the laboratory, they are able to quickly focus on the measurements to be made without the obfuscation previously caused by too many knobs too soon. The design is based upon the user interface of the Macintosh(TM) computer. The A/D hardware interface is based on an inexpensive single-board computer (SBC). Software, custom programmed in the Forth language to implement the virtual scope concept, links the two computers. The author designed and implemented the SBC hardware and the Macintosh(TM) and SBC software. Fifteen systems were built by an undergraduate student technician during the summer of 1988. The devices are currently in use in the undergraduate laboratories at UTK. The paper discusses the design philosophy and implementation of the hardware and software. In addition, use of the computers for simulation and modeling by the Sophomore ECE students in the circuits laboratory is briefly discussed.
