100 Coin Star: Difference between revisions

'''100 Coin Stars''' are [[Star|stars]] that appear after collecting 100 coins in all 15 [[List of Courses|main courses]]. They differ from all other stars in the main courses in that they appear directly above Mario instead of at fixed location. 100 Coin Stars appear in no other courses, even if the player manages to collect 100 coins. 100 Coin Stars are unique in that when Mario collects one, he is not ejected from the current course back to the castle. Instead, a [[Textbox|textbox]] appears, and Mario is allowed to continue exploring the course.

==Phenomena==

{{Merge|Coin Limit|type=section|reason=duplicated information|date=December 2018}}

====Coin Count vs. Coin Display====

The game uses two different variables to track Mario's coins: the ''coin count'' and the ''coin display''. The former is updated the instant Mario collects a coin, while the latter is used to display the coin count on-screen.  

The coin display will increment by 1 until it catches up with the coin count. In particular, the coin display only increments when it is less than the coin count and the [[Global Timer|global timer]] is odd. Using this method, the programmers intended the coin display to update once every two frames. However, by manipulating the global timer through [[Pause Buffering|pause buffering]], one can prevent the coin display from updating altogether<ref>https://youtu.be/T-YtojVHfKc</ref>.

====Coin Overflow====

Both the coin count and the coin display are stored as 16-bit signed shorts, so their values can range between -32768 and 32767 inclusive. In all versions of the game after the original Japanese N64 version, the coin count is capped at 999 on every frame. However, in the Japanese version, a bug is present in the game's code that sets the life counter to 999 when the coin counter exceeds 999:

  // On every frame...

  if (lives > 100)  

  if (coins > 999)

     lives = 999;  //! this should use "coins" instead of "lives"

The effects of this bug are twofold: the coin count can exceed 999, and the lives count is erroneously set to 999.  

Since Mario's life count is stored as an 8-bit signed byte, when it is set to 999, the upper byte is discarded and the number that is stored is -25. Since the above code runs every frame, Mario's life count is constantly set to -25. This means collecting [[1-Up Mushroom|1-Ups]] will not change this value. Since Mario's coin count is not reset when he exits a level, losing a life will also not change the life count until another main course is entered. However, once Mario's coin count becomes negative, the life counter can be modified again.

==Uses==

Because 100 coin stars can spawn anywhere you can collect a coin, they are useful for various challenges.

===A Button Challenge===

When Mario is in freefall, if he is close enough to an edge, he will perform a ledge-grab. In doing so, his height will be updated to the height of the ledge above him, awarding him a small height bonus. Since Mario cannot ledge-grab after dive recovering, dive recovering near a ledge in the A Button Challenge forfeits this height bonus. In certain scenarios, one can use the [[Star Dance Clip]] (SDC) to gain this height bonus without pressing A. When Mario collects a star, his action is set to one that allows him to perform a ledge-grab, regardless of his previous action. If he is close enough to a ledge, he is placed on top of it before doing his star dance animation. Since 100 Coin Stars do not eject Mario from the course, players can use this height bonus to collect stars without pressing A. The Star Dance Clip can be used in combination with [[Vertical Speed Conservation]], which puts Mario into a free-fall state, by ground-pounding to gain height before collecting a 100 Coin Star.

*along with a [[Crazy box]] and three [[Scuttlebugs]] to reach the mansion roof in [[Big Boo's Balcony]] 0x<ref>https://www.youtube.com/watch?v=CLksdecIacA</ref>

*to go to [[Hazy Maze Cave]] 0x<ref>https://youtu.be/uDtInisrqqM</ref>

*to get to the highest walkway 0x in [[Stomp on the Thwomp]]<ref>https://www.youtube.com/watch?v=98EpPsaAF_k</ref>

among other A press saves.

===No Joystick Allowed===

The 100 coin star is currently used to reset Mario's ascent of steep slopes, which is useful near the top of the pyramid in [[Shifting Sand Land]] to collect the stars [[Inside the Ancient Pyramid]] and [[Pyramid Puzzle]].<ref>https://www.youtube.com/watch?v=I1XgaxgpEHA</ref>

==References==

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