Perpendicular Snap Confusion

I have a general question regarding Autocad's Perpendicular Snap behavior. There are times when I am running Osnaps (with osmode set to 767) and I click near a line or intersection and the Osnap goes to a Perpendicular snap on the first click. This is different from the tentative perpendicular snap that shows the .. next to the snap symbol. This is the real snap point that starts the line at that exact point. I am confused by this since I can't understand how you can generate a perpendicular point with only one click. The perpendicular point must be perpendicular to something so I would think that you need at least two sources of input. Does anyone have an explanation for this?
Zachary Kane

It's dangerous to run with the perps IMHO.
Specify version.

2000i 2005 I just got this to happon in 2005. By moving the mouse around a dimension I got the Perpendicular snap to pop up on the end of my slash mark. When I view the line it is actually a short distantance off of the slash mark:
DIST Specify first point: Specify second point: Distance = 0.00144113, Angle in XY Plane = 45.00000000, Angle from XY Plane 0.00000000 Delta X = 0.00101903, Delta Y = 0.00101903, Delta Z = 0.00000000
Where is the world did this point come from??
I do recogize that there is a danger with running with perpendicular on as with nearest. There would be less danger if Autocad would only use perpendicular on the second click!
Thanks Zac.
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zachary snipped-for-privacy@hotmail.com (Zachary) wrote in
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wild guess...... your last point, the point autocad would have used for the @ sign
whatcha think?
roy