To get all the ammo you want edit the savegame file (.SAV) in hex.
 Change locations 75 and 77 or relative sector 0000 to AA and AA. This
 will give you negative munitions. The funny way that numbers behave
 will now mean that you have unlimited shots.
 
 
 Terminator Rampage
 
 Cheat Mode:
 Please note that these codes are for Programmers/Testers only, 
 so don't bug the crap out of Bethesda Softworks about problems 
 with them. 
 Also note: THESE WILL NOT WORK IF YOU HAVE A JOYSTICK INSTALLED 
 ON YOUR SYSTEM! With that in mind...
 
 Hold down the keys RGKO:
 
 Code    Result
 --------------
 CTL+1 - Full Map 
 CTL+2 - All Weapons 
 CTL+3 - Unlimited Ammo 
 CTL+4 - No Damages