Section 4: Using HP-41C Functions62
The only key locations that cannot be reassigned are: g , ON , USER , PRGM , and ALPHA . Any function that appears in the CATALOG can be reassigned to any location. Numbers and ALPHA characters, however, cannot be reassigned. The ALPHA mode functions ( AVIEW , APPEND , ASTO , ARCL ) can be reassigned to the keyboard for execution in USER mode.
If you attempt to assign (using ASN ) a function whose name does not exist in the calculator, the HP-41C will display NONEXISTENT. The ASN function cannot be recorded as an instruction in program memory.
There are 68 key locations that can be reassigned. To assign or reassign a function to a key location:
  1. Press g ASN . The HP-41C prompts you for the function name with ASN _.
  2. Press ALPHA to place the HP-41C in ALPHA mode and enter the name of the function you wish to assign.
  3. Press ALPHA to place the HP-41C back into normal mode.
  4. Press the key (or g and the key) to which you wish the function assigned. If you hold the key down, the display will show function name and the reassigned key by keycode.
Keycodes are a row-column identification of a key location. For example, the keycode for the LN key is 15. The 1 indicates the first row and the 5 indicates the fifth key.
The keycodes for shifted key locations are keycodes prefixed with a – (minus sign). For example, the keycode for the ex key (shifted LN ) is – 15. The – indicates a shifted key, the 1 indicates the first row, and the 5 indicates the fifth key.
For example, assign the MEAN function to the   key.
Keystrokes Display    
g ASN   ASN _   The HP-41C prompts: Assign what?
ALPHA   ASN _   Places the HP-41C into ALPHA mode.
MEAN  ASN MEAN _   The function name you wish to assign to a key location.
ALPHA   ASN MEAN  _   The HP-41C prompts: To which key?
    ASN MEAN  13   Press and hold   for a moment to see the assignment. MEAN is now assigned to row 1 column 3, the   key location.
When you reassign a function to a key location, you may wish to write the function name in the appropriate place on the overlay (provided with your HP-41C) and place the overlay on