The second and fourth tiles in each highlighted group are pieces of the block behind the title logo. The bricks and Bowser's bridge may have each used four unique tiles at some point in development, judging by the arrangement of existing tiles in the CHR data. Only the latter is used by the game's valid levels. There are two identical scroll stop objects: 46 and 47. Map 01 (Worlds 2-2 and 7-2) has a third level pointer for World 3, which leads to the same place as the normal World 2 and 7 level pointers. RAM address 03F0 keeps track of the number of blocks hit, though no routine ever reads the value stored here. This behavior is left unchanged in the Japanese Super Mario Bros.
However, this is not the intended behavior, and is actually the result of a bug! The eggs are supposed to be thrown out relative to the player's speed, Lakitu's speed, the player's position, and a pseudo-random value, as well as bounce off of any blocks or walls that they hit on the way down. The Spiny eggs are thrown by Lakitu in a simple straight-down way, with no horizontal movement whatsoever. This setting is also used in cloud bonuses and World 4-2's vine warp zone, however the current level's timer is still valid there, so this setting goes ineffective.Ĭoin rooms (such as the one in World 1-1), water bonus (World 5-2) and World 8-4's water portion, however, use setting 1. While this setting is used by intros (such as the beginning of World 1-2), the game doesn't actually use the setting, since it completely disables the timer in these levels. Likewise, the timer starts at 000 (causes instant death on normal levels) if this setting is set to 0 ( 00xxxxxx).
The timer starts at 200 if this setting is set to 3 ( 11xxxxxx), though no valid level actually uses it. The upper 2 bits of the first level header setting byte determines the starting timer. (Source: doppelganger's SMBDis (Setting Table)) Unused Timer Setting It's so ubiquitous, people can't get rid of these carts once they have them. This game cemented Mario as the most famous plumber to grace televisions, with compelling gameplay, catchy music, and good graphics. was, and still is, probably the most well-known and biggest-selling NES platformer ever, especially since it was included with most NES units either by itself or with Duck Hunt. See also: the todo on the prerelease page
Document the internal level layout order.