I was introduced to Stephen Hawking at a lecture he gave at MIT around 1989. I asked him about the computer system he was using and he replied in the synthesized voice of the computer:
This system allowed me to communicate much better than I could before. I can manage up to 15 words a minit. I can either speak what I have written, or save it on disk. I can then print it out, or call it back, and speak it sentence by sentence. Using this system, I have written a book, and dozens of scientific papers. I have also given many scientific and popular talks.
I asked if I could take a picture of him with his screen and he smiled a small smile.