Fanuc 6M/16/18/21/16i/18i/21i

1. Select EDIT mode on the mode select switch
   
2. Turn OFF the memory protect key switch
   
3. Press the PRGRM key to display the program screen
   
4. Key in the letter "O" and the number "1234", then press the INSERT key
   
5. Press the EOB key, then press INSERT
   

Yasnac LX and MX series

1. Set Edit Key switch to I.
   
2. Select EDIT mode.
   
3. Press the Prog soft key underneath the screen.
   
4. Type in the letter O and a four digit number such as 1234 and then the WR key. This is the only time the WR (Write Key) is used during program editing
   
5. The program screen will now be blank except O1234; in the upper left corner. The cursor will be highlighted on the EOB character ; .