Okay so this post is a few weeks old now but the talking computer you have heard about probably refers to screen-reading software which, when installed, reads a computer screen aloud. Apple products have one built in called Voiceover which can be turned on in settings. Windows PCs work with a couple of screen-readers, the most popular being called JAWS.
There are also electronic braille note takers which are effectively computers but where the keyboard and screen is Braille: very expensive and probably not the path I would go down especially as I assume he doesn't know Braille. I would try to encourage him to learn at least the Braille alphabet: you could do this by learning with him. My mum practiced by getting very easy-to-read children's books and brailling the story on clear card which was stuck over the print. It could be something fun that you learn together.
Sorry to input in to an old post but I thought it may or may not be helpful.