The chip that would read RAM and generate a video signal was called a CRTC or RAMDAC back in the day - though RAMDAC, standing for RAM Digital to Analog Convert

The chip that would read RAM and generate a video signal was called a CRTC or RAMDAC back in the day - though RAMDAC, standing for RAM Digital to Analog Converter, only really applies to VGA which is analog. Some game consoles had an equivalent chip (Brooktree/Conexant) that was called an encoder. This is separate from anything that blits textures, rasterizes triangles to video RAM, performs parallelized math operations on big vector lists, runs shader code, or does MPEG/etc. decoding. All of that stuff is what constitutes a GPU. I'm not sure what the modern term for DAC is given everything is all digital.