24 Mar
2017
24 Mar
'17
1:51 p.m.
Geoffrey Oltmans wrote:
I can imagine that they employed a similar vector
generator on the Vectrex.
The 6809 processor had to go through the display list itself. But the
analog design was very clever. To draw a vector you would use the single
DAC to set the start x voltage, then use the same DAC to set the start y
voltage, then the end x voltage and finally the end y. The analog
circuit would then draw the line itself at a constant rate and the 6809
was free to work on other stuff until the line was finished. So the
processor didn't spend time on Bresenham's algorithm and drawing dots
like some other vector displays.
-- Jecel