[Coco] Vertical yellow bar fix (CoCo2 Video)

[Zippster]

Hello everyone,

Luciano Scharf asked me earlier today about a problem he was having with the video output 
on his CoCo2.  A vertical yellow bar was appearing on the left side of the screen.  I had a machine
on hand that was exhibiting the same thing, so I investigated the problem.

It turns out it’s an issue relating to the color-burst circuit in the CoCo2.  I’ve written up details on
the cause, and a way to fix the problem here…

<https://sites.google.com/site/thezippsterzone/home/coco2-projects/vertical-yellow-bar-fix <https://sites.google.com/site/thezippsterzone/home/coco2-projects/vertical-yellow-bar-fix>>

- Ed