Writing to the Framebuffer
There may be more than just one simultaneous framebuffer per display on the hardware level.<p>GPUs can actually scan to a display from <i>multiple overlapping framebuffers</i> in different resolutions and color formats <i>in the same time</i>. Alpha blending and rotations are often supported as well.<p>A bit like a very large mouse cursor. In a way, mouse cursors are also framebuffers. Or like hardware video layers in the nineties.