Comment by dcrazy
1 day ago
> Old Nintendo consoles like the N64 or the GameCube/Wii didn't have programmable shaders.
The N64 did in fact have a fully programmable pipeline. [1] At boot, the game initialized the RSP (the N64’s GPU) with “microcode”, which was a program that implemented the RSP’s graphics pipeline. During gameplay, the game uploaded “display lists” of opcodes to the GPU which the microcode interpreted. (I misspoke earlier by referring to these opcodes as “microcode”.) For most of the console’s lifespan, game developers chose between two families of vendor-authored microcode: Fast3D and Turbo3D. Toward the end, some developers (notably Factor5) wrote their own microcode.
Microcode was only used for the RSP, which was a modified MIPS coprocessor and could only realistically be used for T&L. After that, the RSP then sends triangles to the RDP for rasterization, pixel pipeline, and blending, all of which are fixed-function, admittedly with some somewhat flexible color combiner stuff.
I appreciate the correction. Still, programmable T&L was kind of a big deal. PC GPUs didn’t get hardware T&L until the DX7 era, and it didn’t really become programmable until DX9/Shader Model 2.0.