I'm a long-time user of the TI-89 (through hs, college, and now for business accounting) - has anyone solved the input problem? The keypad is only good for arithmetic and symbology, typing text is pretty awful.
According to http://punix-os.blogspot.com.br/2012/03/floating-point-grays... they want to add support to PS/2 keyboards through an adapter.
This http://education.ti.com/educationportal/sites/US/productDeta... also seems like a good solution.