a PIC16F84 drive servo motors. It receives commands from a host computer via a standard RS232 serial interface. Supports 4 servo motors and 4 digital outputs. Can be modified for 8 servo motors.
http://www.digitalnemesis.com/ash/projects/picservo/
a simple 0-10 volt voltage to pulse width circuit.
http://home.att.net/~northlightsystems/applications.htm#Hobby
gives you 256 different positions over the full range of the servo
http://www.geocities.com/SiliconValley/Lakes/7156/articl4.htm
It is a servo tester based on 556N chip. PCB design files are provided.
http://www.speedy-bl.com/servo-e.htm
with PIC microcontroller
http://www.imagesco.com/articles/picservo/04.html
wirings and signal used with RC servo motors
http://www.vantec.com/servo.htm
example program for PC written in BASIC
http://www.armory.com/~rstevew/Public/Motors/Servos/servopgm.bas
with PIC microcontroller
http://www.imagesco.com/articles/picservo/02.html