Hi Charlie,

At 4Mhz OSC, the resolution of PULSOUT is 10us.

The range of pulses required for servos is from 1.05ms - 1.95ms. That's a difference of 900uS. With 10us resolution you will get 90 steps of about 16 degrees each. Assuming a 4-turn rotary.

At 20mhz the resolution is 2us, which will give 450 steps of about 3.2 degrees per step.

At 40mhz you can get 900 steps of about 1.6 deg/step.

Or, at 4mhz you can use this program to get 900 steps too.
PWPS (Pulse Width Position Servo)
http://www.pbpgroup.com/modules/wfse...hp?articleid=2

HTH,
  Darrel