Its not worth the effort. Buy a PDA.

However, if you have a better need to store displayed information, you need a micro to monitor and analyze the display control lines and possibly to control the keyboard interface too.

One sememster while I was working on my graduate degree in finance, I needed to do something electronic for variety. I hacked into an old radio scanner of mine and added my own microprocessor interface.

It monitored the display control lines so that it could effectively read the display, timestamp it and upload the information to an old PC over a commlink. It also took commands from the PC commlink to make the scanner think human keystrokes were configuring it.

With this arrangement, I could have the PC schedule band sweeps and timestamp the signals it found and then bump the sweep past it to find others. It was a great tool for radio scanners.

If your lucky, your intended target display is mounted off the microprocessor PCB and thus you merely need to tap the control cables running between the two and add your non-intrusive interface. Its fun though seldom practicle. :)

aka J