From some of my earlier investigations, handicapped computing support is astonishingly bad and expensive. Largely because many things are near one-off limited-use solutions that can't be re-sold... but nothing is ever modular or adjustable or could be tweaked to be used in multiple situations anyway. The DIY crowd for such things, meanwhile, keeps hacking up things like this for almost no money.

And it only gets worse once you come to software. Hardware interfaces have a general communication format - websites do not. Applications do not. Almost nobody makes software with hinting for assistive devices, despite tools and standards existing. I suspect it's mostly because it's extra work, and doesn't (usually) significantly help to pay the bills when added.

If you mean an output device based on Braille, then yes, you can get a Braille terminal, or "refreshable Braille display" (http://en.wikipedia.org/wiki/Refreshable_Braille_display), which displays a row of characters via Braille, and can indicate the cursor position as well. That would make it possible to interact with the command line. They appear to cost about $5-10k, depending on whether you want a 40-character or 80-character row of characters.

You might also look at http://live.gnome.org/Orca , which helps you interact with graphical programs via both speech and Braille (and magnification for as long as you continue to have some vision).

As far as "input devices based on Braille"; you can probably get a keyboard with Braille lettering on the keys, but if you can touch-type you don't really need the labels anyway.

Hope that helps.