Use the Easy Java Simulations Modeling and Authoring Tool to edit and to explore the source code for the Two-Body Orbits JS Model.

Changes made by lookang include

added the invisible mass for which the binary system's motion are derived from.
added the velocities v1x, v1y and v2x v2y
added velocities checkbox
added units labels clearly showing units a.u. and year
added combo drop-down list for ease of use
added numerical values for sense making such as F1, F2, a1, a2, R1 and R2 v1 and v2
made forces a bit longer to see more clearly