Later Dragon 32s and Dragon 64s used a non-standard 14.218MHz crystal in place of the early Dragons' much more common 14.318MHz crystal. The change was to remove some of the resonance in the display circuit, and the 14.218MHz can help improve the picture generated by a 14.318MHz crystal.
The crystals were commissioned specially by us for the repair and improvement of Dragon 32s and Dragon 64s!