Render sprites or textures with pixel precision to a 640x480 RenderTexture, then draw that fullscreen

I'm making a game, and in part of it, the player uses a computer terminal. I want to draw to a virtual 640x480 screen with pixel precision, put that in a RenderTexture, and then draw that RenderTexture to the screen. The outcome is not going to be "pixel precise", because I'll be scaling the texture to whatever screen size the user is using (and then, later, doing more effects on top of that), but I just want to know how to render stuff with pixel precision to a RenderTexture. Sorry if this is too nooby of a question, I'm an experienced programmer who is relatively new to Unity.

EDIT: To clarify, I don't need to pixelate any assets or textures or anything, I basically want to have sprites (or textures or whatever) for text characters, and draw them to the "virtual screen" like this: