Arrow keys = move trackball right/left/up/down
Function key - CTRL + number
Tab = CTRL + i
CTRL = press trackball once.
ConnectBot is an Android SSH client which runs on older versions of Android also. It could import the RSA key pair once I copied it to memory card from my Linux desktop's .ssh directory. In order to use Ctrl, Esc, Func and arrow keys, it uses the trackball.ESC = press trackball twice