Notes
1. DynavoxVTM and DynaWrite are products of Dynavox Technologies, Pittsburg, PA.
2. The PRC Echo2 is a product of the Prentke Romich Company, headquartered in Wooster, OH.
3. LightWriter is a registered trademark of Toby Churchill, Ltd. Cambridge, England, distributed in the USA by Zygo Industries, Inc., PO Box 1008, Portland, OR 97027-1008, USA.