SM64 - The 255 Coin Limit

The video addresses common questions about the 255 coin limit in Super Mario 64, explaining that while the in-course counter can go up to 999 coins, the saved score is subject to a different limitation. The counter will continue past 255, but stops at 999. Mario can still collect more coins, but they won't add to the displayed total. This means the in-course coin counter is distinct from the saved coin score.

The actual coin score that gets saved is determined by applying a modulo 256 operation to the total coins collected in the course. If 999 coins are collected, for example, the saved score becomes 231 (999 divided by 256 is 3 with a remainder of 231). This means that multiple in-course coin totals can result in the same saved score. The maximum savable coin score is 255, which is achieved by collecting 255, 511, or 767 coins.

It's possible to lower a saved coin record. For instance, if a player has a saved record of 231 and then collects 256 coins, the new saved record will be 0 (256 mod 256). This technique allows players to achieve any coin record between 0 and 255, provided the course has an infinite coin glitch.

The 999 coin limit within a course was an intentional design choice by programmers, a cap set via a line of code. However, the 255 coin limit for saved scores is an unintentional outcome, purely a result of how coin records are stored in memory using 8 bits. The game uses a binary system, where 8 bits can represent numbers from 0 to 255. Any number larger than 255 loses its higher bits when being saved, effectively applying the modulo 256 function.

The in-course coin score is represented by 16 bits, allowing for a capacity of up to 65,535. However, the saved coin score uses only 8 bits, which caps its maximum value at 255. When a 16-bit number is saved to an 8-bit space, only the lower 8 bits are retained, leading to the modulo 256 effect and the 255-coin limit.

The video then explores the maximum coin scores achievable within each course, aiming for the in-course maximum of 999 where possible. For courses like Bob-omb Battlefield and Whomp's Fortress, infinite coin glitches (like the disappearing cork box trick) allow reaching 999 coins. For courses without infinite coin glitches, the limit is simply the total number of coins present.

In Big Boo's Haunt, while a coin can be cloned, it doesn't lead to infinite coins because the 'crazy box' that produces it doesn't respawn, and the available coins for cloning are enemy coins, which don't regenerate by leaving and re-entering the area. Furthermore, the game has object slot limitations (240 total), which can cause freezes if too many cloned objects are present.

Some courses with cloning glitches, like Dire, Dire Docks and Wet-Dry World, can reach 999 coins because 'loading points' cause clones to disappear, preventing object buildup. In Tall, Tall Mountain, entering a slide resets the course state, removing clones and allowing for 999 coins. Cool, Cool Mountain allows reaching 999 by duplicating and killing Moneybags, but warns against creating too many at once due to potential game glitches.

For Tick Tock Clock and Rainbow Ride, where cloning is the only infinite coin glitch but there's no way to unload clones, achieving the true maximum requires careful management of object slots. This involves collecting all one-ups and minimizing active objects to make room for cloned coins. Precise bomb explosions are necessary to avoid using too many object slots for smoke and explosions, which can freeze the game.

Tick Tock Clock has an object slot limit of 239. The video demonstrates the meticulous process of cloning coins while managing object slots. This includes collecting all but one cloneable coin, precisely detonating Bob-ombs, and even strategically positioning a bomb to allow for a final clone before hitting the object limit. The maximum achievable in-course score for Tick Tock Clock is determined to be 279 coins.

In Rainbow Ride, which has a maximum of 227 objects, the strategy is similar to Tick Tock Clock but introduces the concept of 'important' and 'unimportant' objects. Unimportant objects, like wind particles, can be overwritten if object slots are full. The wind on the ship counts as 30 unimportant objects. Careful management is needed to ensure at least one slot remains for wind particles, preventing a freeze. Avoiding activating the cannon is crucial, as it adds a permanent object, reducing the maximum coin score. The maximum obtainable score for Rainbow Ride is 209 coins, due to strict object management.