Section 1: Getting Started23
Keystrokes Display    
     HYD _   Another right most character deleted.
RO  HYDRO _   The correct word.
ALPHA   0.0000   Takes the HP-41C out of ALPHA mode.
In normal mode, when you are keying in a number, you can use    to delete and correct digits in the number. For example, key in Joule’s constant (the equivalent of a Btu in ft-lb), 778.26. Again, notice how the ‘‘_’’ prompt moves.  
Keystrokes Display    
778.36  778.36 _   Whoops, Joule’s constant is 778.26.
     778.3 _   One right most character deleted.
     778. _   Another character deleted.
26  778.26 _   The correct Joule’s constant.
In both ALPHA and normal modes,    only works as a character-by-character correction key when the _ prompt is in the display. If the _ prompt is not present in normal mode, then pressing    clears the X-register to zeros (like a CLX ). The    always deletes one character at a time when you are keying in ALPHA characters.
The    key can be used in many different situations to aid you in correction of entries and error recovery. You will learn more about the    function as you progress through the handbook.
In spite of the large number of functions available in the HP-41C, you will find all functions simple to execute:
  • When you press and release a function key, the calculator immediately executes that function.