Cliff Rogers wrote: > G'day, give this a go, it has links to more as well. > http://werple.net.au/~tonymerc/steptheo/steptheo.htm > Cliff Rogers (Computer Technician) email cliffrogers@usa.net > Absolute Computers Pty. Ltd. Cairns, Queensland, Australia. > Actually it's a very interesting page and I enjoyed it. But it's not about servos it about steppers. BUt traversing the links gave me ideas for an excite search and I've refound the Seattle Robotic goupand other useful links. (I really have to back up my bookmarks). What I have is a motor from a hard disk, the motor controlled the head position via a gear drive. It has 4 wires which enter the motor and 4 wires which go th a light emitter and detector (2 wires for each). What I'm trying to discover is what wire do what for the motor. There has to be power (most likely 12v) and ground. Then there are the other 2, I suspect this motor is a servo and one is the signal in and the other signal out(???). Any ideas.