To play as Smoke:
-----------------
At the Copyright or Raiden screen (while/after loading), rotate
the directional pad clockwise to access the UKK screen. At the kombat
cube, push up to get the blue ?. Then enter:

0     1        0          6        9   6
L1 + R1 + square + triangle + circle + X

(The numbers refer to how many times you must press the
corresponding button. Do not play before entering this code.)

- Various sources....

Cheat Menu 1
============
To access the "extended options" menu (Fatality time, Smoke etc.), at
the copyright screen press X, L1, L2. You'll hear a woosh. Now, on the
Kombat menu, press up for the blue ?.
 
Cheat Menu 2 (Must be done after doing the X, L1, L2 code) 
============
 
After the "Prepare for Kombat" screen apears press X,O,Triangle,R1,R1,R2,
R2,R1,R1 then you will hear "you will never win" from Shao Kahn.Then
press start on the kombat screen (were cont.config. and game config is)
press up you will see a question mark (?).Now press O,X or anything you
will see the cheat with 2 more options.
 
                                        Marcos Barcenas

I found that on the Australian version the cheat code should be
X,O,Triangle,L1,L1,L2,L2,L1,L1.
 
Ian Evans


VS. SCREEN CODES
Blocks Disabled - 020 020
Combos Disabled - 722 722
Dark Kombat - 688 422 
No Life Bars - 987 123 
P1 Half Energy - 033 000 
P1 Quarter Energy - 707 000 
P2 Half Energy - 000 033 
P2 Quarter Energy - 000 707 
Play Cheesy Galaga Clone - 642 468 
Psycho Kombat - 985 125 
Randper Kombat - 460 460 
Throws disabled - 100 100 
Unlimited Run - 466 466 
Winner Fights Motaro - 969 141 
Winner Fights Noob Saibot - 769 342 
Winner Fights Shao Kahn - 033 564 
Winner Fights Smoke - 205 205 

Real Kombat - 040 404
Super Endurance - 024 689
Rgenerating Powerbars - 975 310