WSI, an importer in So. Cal was accidently sent a few Raleigh Bicycles. They were told they could keep them if they removed the labels. This sparked an interest in importing bikes and Diamond Back was started. DB stands for "Dirt Bike". So many greats..Harry Leary, Eddy King, and more..
The Turbo bike, Silver Streak and more.!. 

Diamond Back reference charting the History between 1977 to 1986, including detailed model information & a supporting forum

For more info, check this out:

www.os-db.net