This armor is unlocked by going to the 'Character Select' screen and pressing O(2), Left (6) and then holding L1 and R2 until the game starts. If you have entered the code correctly X's body will be a purple color and when you go to where you get the Leg Capsule in Web Spider's level you will get the Ultimate Armor.

Unlock Ultimate Armor for X:
At the 'Character Selection' screen highlight X and Press Circle, Circle, Left, Left, Left, Left, Left, Left and then hold L1 and R2 until you enter the first stage. After the first stage go to the Jungle Level and go to where the Leg Enhancement would be Ultimate Armor for X.

Unlock Megaman's Ultimate Armor, Nova Strike and Aerial Attack:
Enable the X's 'Ultimate armor' code and play through the first two introduction levels. Then begin the Jungle level and go halfway down the second waterfall and to the right and enter the capsule.

Unlock Zero's Black Armor:
Highlight Zero at the player selection screen and hold R1 and press Right(6). Then release ALL the buttons and hold Circle and press Start.


Boss Weaknesses
The following is a list of each Boss and their weakness to their own weapons.

Ray - Walrus' weapon

Dragoon - Owl's weapon

Spider - Beast's weapon

Walrus - Dragoon's weapon

Mushroom - Spider's weapon

Owl - Cyberpeacock's weapon

Cyberpeacock - Mushroom's weapon

Sigma Out Of Robe - Spider's weapon

Sigma In Ghost Robe - Dragoon's weapon