The simulation program AORTA, version 0.x (Sikken & Min, 27 febr. 1997), built with JavaTHESIS. In this prototype no interventions with parameters (as Rp and Cao as shows in the text) are possible. (That's coming.) This isn't a function display program. This is a monitoring system. It is slow but that's what we like: so students have time to think about what happens.