CPC1100, at a guiding scale of 1 arcsec/pixel, with data collected with PHD. Guiding commands were turned off about 20 seconds into this graph. Target was on the equator, about 1.5 hours east of the meridian. PEC (from data collected with PemPro) was on. The vertical scale is in pixels (and thus arcsecs), the horizontal scale is divided per 25 datapoints. Datapoints were approximately 1 per 1.7 seconds. The "cycle" in RA thus appears very close to the 480 second worm cycle. Peak-to-peak RA motion was about 10-12 arcsecs, and the guide star was relatively stable for two to three minutes at the extreme points (which are just off this graph's Y axis). True declination drift (subtracting out the apparent correlation with the RA error) appears to be about 0.3 arcsecs/minute.