XPost: sci.electronics.design   
   From: jasen@xnet.co.nz   
      
   On 2013-02-14, DaveC  wrote:   
   >>   Not if it is a video clock, to a fixed frequency monitor.   
   >   
   > I learned a little more about this circuit.   
   >   
   > It's a proprietary video card card from a piece of German offset printing   
   > equipment.   
   >   
   > I used a sig. gen. in place of the crystal. The circuit generated a video   
   > signal without any data (just sync pulses). The video card is separate from   
   > the system processor, so being on the bench the card has no data to display.   
   >   
   > Viewed on a scope, varying the 8.867 MHz frequency doesn't change the video   
   > signal at all.   
   >   
   > I'm guessing (with my limited understanding of how video works) that the   
   > 8.867 runs the dot clock, basically how fast the dots are shoved out of the   
   > data bus into the video generator IC.   
   >   
   > So, how critical *is* this frequency?   
      
   it's hard to say. it depends on the monitor.   
   try a 9MHz crystal it's within 2% of the target , you might need to tweak the   
   vertical and/or horizontal hold adjustemnt on the monitor.   
      
   http://www.mouser.com/ProductDetail/ECS/ECS-90-S-4X/?qs=sGAEpiMZ   
   MsBj6bBr9Q9aWDZfF25lWfiN%2f2lvWpfTc0%3d   
      
      
   --   
   ⚂⚃ 100% natural   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)