ST3500320AS successfully recovered from BSY error. I just register to say a big thanks to all of you for the useful information and a special thanks to Gradius for posting the solution. I recover my data for only 2 euros (I've already had some equipment though) using a circuit shown below. I will just stick to one thing that I had difficulties to solve. The only way to get response on the terminal was to block the motor contacts with a piece of paper. after that i followed the instructions mentioned in the first page of this topic and i've got my data back .