"...but how many different model is there in the world...?"

He is using a standard chinese clock-drive for an EQ4/5 scope - so am I. I was expecting our motors to be identical....

"You can now buy a sound card under 20$ here.."

I have some separate sound cards already - I was assuming that you plugged the probes into the game port on them. But now I have downloaded VA, I see there is no info about where to connect the probes to at all. Do you connect the probe to the 'microphone-in'? If so, I can connect it to the built-in sound card on the motherboard of the system I am using. It is odd that there seems to be no information about this vital point...?

"When i talked about the original design, i meant your previous one.."

Sorry - I misunderstood. In fact, I still have the original handcontroller. My problem is not that it was broken, but that it drove the motors at the correct speed for an EQ4/5 mount (1/10 rpm) and I wanted to use it for an EQ3-2 mount (1/11 rmp). Those are the final speeds - there is a gear train of approx 200:1 between the scope and the stepper. The original controller used an Amtel micro, directly driving an array of 8 transistors. They could well be MOSFETs.