Abm6

  X
 ======
 ~~~~~~
 ------
 ||2|||  3rd fret
 ------
 1||333
 ------
 ||||||
 ------
 A FCEA
 b  bbb

or:

  X   X
 ======
 ~~~~~~
 ------
 ||1|||  3rd fret
 ------
 2||34|
 ------
 ||||||
 ------
 A FCE
 b  bb 

or:

   X   
 ======
 ~~~~~~
 ------
 1||1|1  4th fret
 ------
 ||||||
 ------
 |3||4|
 ------
 ||||||
 ------
 AE CFA
 bb b b

or:

 XX
 ======
 ~~~~~~
 ------
 ||1-1|  6th fret
 ------
 |||||2
 ------
 |||3||
 ------
 ||||||
 ------
   AEFC
   bb b

Notes:  1  : Ab
        m3 : Cb
        5  : Eb
        6  : F