EDT Backspace (Start Of Line)

  Moves the cursor back to the start of a line.

  Key:   The EDT keypad defines both CTRL/H and F12.  On VT100-series
         terminals, the BACKSPACE keys is the same as CTRL/H.

  Usage notes:

  o  At the start of a line, EDT Backspace moves to the start of the
     previous line, if there is one.  Thus, you can repeat the key until you
     reach the top of the buffer.

  Related topics:

     END OF LINE    MOVE BY LINE    START OF LINE    TOP