http://bear.ras.ucalgary.ca/glen_home_page/radast/user/node23.html (Einblicke ins Internet, 10/1995)
A list of seven available options are displayed in a box at the upper left of
the initial screen. A second box near the lower left corner of the initial
screen has the two additional options solve and quit. To choose any
one of these options, move the highlighting bar
until it lies over the option that is to be selected and press the Enter
key. Movement of the blue highlighting bar is acheived through the 
and 
cursor control keys on the keypad. A
description of each of the available options is given below.
The Escape key is very useful when errors are made in choosing
options or solving for the 
-
coverage. If the Enter key has
accidentally been pressed, pressing Escape at
any time will abort that operation and return the user to the command level.
If solve is running when
Escape is pressed, then the computer halts execution and returns to the
command screen.