It is not an emulator, but with GUICANVAS you can generate screens of any size and manipulate their pixels:
// GUICANVAS by @SalatielSauer (01/09/2023) // github.com/CubeScript/Sauer-GUICANVAS // the screen consists of a model with dozens of meshes, each mesh has an index that is used as a pixel; // the pixel color/texture is set using objskin ; // the model can be loaded in game with `mmodel guicanvas` or in a menu with `guimodelpreview "guicanvas"`;