Tablet PC-based engineering software can be used as an effective teaching tool for core engineering courses such as electronics, signal and systems, and digital systems. Wireless connection between Tablet PCs of students and the teaching professor will substantially improve students' involvement during the course.Circuit drawing is an important task especially in undergraduate courses such as electronics and digital systems. Most existing software tools for circuit drawing use a toolbox where symbols for all circuit components are prepared and ready for pick up. A user has to go through a number of layers of menus each time he/she wants to use a circuit symbols. To improve human computer interaction, we have developed an online recognition system on a Tablet PC using C# for the handwritten circuit and its components. The system can recognize and redraw many circuits and their components such as resistors, capacitors, ground and various voltage power supplies, which are drawn with a stylus pen on a Tablet PC. We present details of our approach and preliminary results of an experimental system.