Heres a better link to the JMI TNT system.
http://www.jimsmobile.com/buy_tnt.htm
Its basically `train n' track' without the 'brain' the DobDriver system has.
You press the speed control until it learns the required speed to follow the object in each axis, but does not do any calculation beyond that, so the rates are only going to be good for 10 minutes or so, depending on where in the sky you are pointed. The Tech 2000 Dobdriver goes beyond that in continuously recalculating new tracking rates as time goes on.
For $399 USD however , its going to be a step up than nothing for high power observation anyhow
