I want to know the answer to the following question:
Where was AT&T's "Picturephone" device unveiled?
All the background I'm provided with is that "The use of sign language via videotelephony was hampered for many years due to the difficulty of its use over slow analogue copper phone lines, coupled with the high cost of better quality ISDN (data) phone lines.". Is that enough to answer the question?
Answer: no