I use exbal on a palm m130, they are cheap, but when the battery dies, you have to re-install everything (volatile memory). So I upgraded to a Palm Tungsten, battery life is better, calculation is blazing fast and it has non-volatile memory.
The cheaper Black and white monitor is easier to see in the sun than my new color tungsten though.
If some is good and more is better, then too much is just right.
My mind is a raging torrent, flooded with rivulets of thought, cascading into a waterfall of creative alternatives