CDC 6600 display character generation

Someone very kindly pointed me at: http://www.bitsavers.org/pdf/cdc/cyber/cyber_70/fieldEngr/60125000C_6602_66… (although why it's in the Cyber70 folder, I'm not quite sure :-). I don't completely understand it (it's only drawings, no text, and the notation is unfamiliar), but I think I get the general drift - and it's pretty baroque! Very briefly, it appears to me that characters are generated from short vector-type strokes placed in a 7x7 matrix, with each stroke being encoded as motion of 0, 1 or 2 'boxes', both horizontally and vertically, from the 'box' of the end of the previous stroke. A character can contain up to 22 strokes, but most seem to average about dozen or so. The pronounced rounding which I noticed in the characters must be caused by the limited bandpass of the A-D system, amplifiers, etc - it can't actually do a sharp corner when going from e.g. a vertical stroke to a diagonal one. Or something like that.. :-) Noel