Google "TV Test Pattern" in their "images" area. There are a ton of them available as jpeg's. If you want to actually use one to set up your old video equipment look for a Micca Digital Media Player at Amazon.com
http://www.amazon.com/Micca-MPlay-Di...keywords=micca or eleswhere. You can save the test pattern on a regular SD memory card, and the Micca player will turn it into composite video. The good news is the player is less than $30. I have one on my work bench and have a variety of test patterns and color bars stored on it. I love it.