У вашего броузера проблема в совместимости с HTML5
Parallax Propeller chip running PropForth and micro-stepping using the L6470. This demonstration is fairly basic but does show the L6470 handling the large stepper and performing it's acceleration and deceleration profile. The chip has been configured to stay in microstep mode which btw is 128 steps/step = 25600 steps per revolution. BTW, I incorrectly stated that it was turning 160 steps but I meant full "turns"