On May 27, 2014, at 1:08 PM, Richard <legalize at xmission.com> wrote:
In article <53839282.9020706 at sydex.com>,
Chuck Guzis <cclist at sydex.com> writes:
On 05/26/2014 11:49 AM, Paul Koning wrote:
> The 6000/7000 series had random access stroke drawn character and dot
> graphics, no vector graphics. (Dot graphics is basically a lot of
I would call that a vector display. It just didn't give you vector
graphics, but that's probably more a limitation of the controller than
The controller has commands for drawing characters, in your choice of 3 sizes, at any base
(lower left corner) X/Y. It also has a command to draw a dot at any X/Y. That actually
amounts to nothing more than drawing a period.
The interface to the display has 9-bit buses for X and Y, and two differential pair analog
connections for the character waveform. It also has two wires to encode the three sizes.
The display circuitry constructs the X/Y deflection signals out of the X/Y position values
(via a D/A circuit) summed with the character waveform multiplied by a character size
scale value. So the interface is not capable of generating arbitrary vectors, only
vectors up to +32 away from the base X/Y. Also, the deflection circuitry bandwidth was
low enough that stepping by more than 8 or so pixels (large char size and the max 2 pixel
step generated by the controller) would probably be problematic; even the regular
character shapes were quite visibly distorted. And the design assumed that the base X/Y
digital data would remain constant whenever the beam is on, so you can?t draw vectors by
changing that value on the fly.