All SNES rom have an internal header that is used to identifying the game, producer, region and technical aspects of the ROM. It's often referred as Internal ROM Header or SNES Software Specification.

Although it's not required to run a game on real hardware, the SNES ROM Header was used during the Nintendo approval process for validation and it's also used by the SNES emulators to identify and determine the memory layout and ROM type.

The data starts at SNES address $00:FFB0 and ends at $00:FFDF. $00:FFE0 though $00:FFFF contains the SNES vector information and it's actually used by the SNES CPU to determine where to execute when an interrupt occurs.

## ROM Registration Data

|ADDRESS|LENGTH|DATA NAME|  
|-------|------|---------|  
|$00:FFB0|2 bytes|Maker Code|  
|$00:FFB2|4 bytes|Game Code|  
|$00:FFB6|7 bytes|Fixed Value|  
|$00:FFBD|1 byte|Expansion RAM Size|  
|$00:FFBE|1 byte|Special Version|  
|$00:FFBF|1 byte|Cartridge Type (Sub-number)|  
|$00:FFC0|21 bytes|Game Title Registration|  
|$00:FFD5|1 byte|Map Mode|  
|$00:FFD6|1 byte|Cartridge Type|  
|$00:FFD7|1 byte|ROM Size|  
|$00:FFD8|1 byte|RAM Size|  
|$00:FFD9|1 byte|Destination Code|  
|$00:FFDA|1 byte|Fixed Value|  
|$00:FFDB|1 byte|Mask ROM Version|  
|$00:FFDC|2 bytes|Complement Check|  
|$00:FFDE|2 bytes|Check Sum|  