Re:TI-89 Titanium (Score 1)

There is an open-source driver you can run as an application to use a PS/2 keyboard rewired to a graphlink connector... unfortunately I can't find the link. But I built an adapter a few years ago for my TI-83, basically you run the TX and RX lines through. Not sure if this is a viable option but I found a link to a pre-built device: http://www.calc.org/webstore/ You might want to try modding one of those fold-up Palm keyboards, it'd be an interesting hack and still portable enough to use. I used to take notes on my TI-83.