2.4.3 Using Microcode

Types of Microcode

Currently, N64 has two types of microcode, graphics microcode and audio microcode.

Graphics Microcode

The commands used in the graphics microcode are called GBI (graphics binary interface) commands. Each GBI command uses 64 bits. Following are some general notes about improvements that Nintendo has made to the graphics microcode:

gspF3DEX Series of Microcode

Sprite Microcode

JPEG Microcode

The N64_JPEG library has two types of microcode, one for encoding and one for decoding.

Audio Microcode

The audio microcode is made up of ABI (audio binary interface) commands. These ABI commands are strung together to form the audio command list. Each ABI command uses 64 bits.