CDC 6600 display character generation

Hi, I'm hoping someone here knows the low-level nitty-gritty on how the characters on the CDC 6600 console CRTs were generated. Thornton, "Design of a Computer", says "Control of the beam .. is provided by electrostatic deflection ... electronically converting from the symbol .. to deflection voltages", but alas, doesn't say how that conversion is done. And I looked in some CDC 6600 documentation online, alas, even less detail. But looking at the characters (reproduced on the dust jacket), the curves sure make it look like it wasn't anything simple (e.g. using display vectors, as one source indicated). Does anyone know? (BTW, the VT11 in DEC's GT40 used bit maps for its built-in character geneator, and the hardware did tiny raster zones to display them!) Noel