I am having difficulty fully understanding the maximum (MAX) read only memory (ROM) sizer for game boy advance (GBA) game cartridges.
Many sources online tell me that the GBA cartridge pin out has enough pins for a 24 bit address,
Pins 6-21: AD0-AD15
Pins 22-29: A16-A23
Using some emulator like visual boy advance (VBA) it can be seen that each address stores 16 bits of data, or 2 bytes. ROM files loaded into VBA appear to be nothing about a text file of American Standard Code for Information Interchange (ASCII) characters. Where each ASCII character is translated into 16 bits by the emulator. So the first character is the data stored in the ROM at the first address.
So the MAX ROM size supported by GBA cartridges is therefore
(2^24 addresses) * (16 bits/address) = 268435456 bits
268435456 bits = 268.435456 Mbits
268.435456 Mbits = 33.554432 Mbytes
However several sources online tell me that the MAX ROM size supported by the GBA is 32 Mbytes, yet I calculate 33.54432 Mbytes. I don't understand what I have done wrong. Any help would be appreciated.
Here's a source stating that the MAX ROM size is 32 Mbytes, which is not what I calculated.
https://www.neogaf.com/threads/what...-cartridge-sizes-of-certain-consoles.1069829/
Apparently Kingdom Hearts was 32 Mbytes
Many sources online tell me that the GBA cartridge pin out has enough pins for a 24 bit address,
Pins 6-21: AD0-AD15
Pins 22-29: A16-A23
Using some emulator like visual boy advance (VBA) it can be seen that each address stores 16 bits of data, or 2 bytes. ROM files loaded into VBA appear to be nothing about a text file of American Standard Code for Information Interchange (ASCII) characters. Where each ASCII character is translated into 16 bits by the emulator. So the first character is the data stored in the ROM at the first address.
So the MAX ROM size supported by GBA cartridges is therefore
(2^24 addresses) * (16 bits/address) = 268435456 bits
268435456 bits = 268.435456 Mbits
268.435456 Mbits = 33.554432 Mbytes
However several sources online tell me that the MAX ROM size supported by the GBA is 32 Mbytes, yet I calculate 33.54432 Mbytes. I don't understand what I have done wrong. Any help would be appreciated.
Here's a source stating that the MAX ROM size is 32 Mbytes, which is not what I calculated.
https://www.neogaf.com/threads/what...-cartridge-sizes-of-certain-consoles.1069829/
Apparently Kingdom Hearts was 32 Mbytes