get itself ready to execute a game) as well as display the iconic splash screen. These 255 bytes are instructions that tell the Game Boy how to 'bootstrap' itself (i.e. Memory can be thought of as one very large array of 8-bit numbers.Īt the beginning of this very long array are 255 bytes (from index 0x0000 to index 0x00FF) that are hard coded into the Game Boy's circuitry. So far we know that the Game Boy has a CPU that executes instructions and it has memory. But how does the CPU which instruction to execute? To understand this, we'll first need to understand where our instructions are stored. So far we've seen instructions that can operate on register data.
