As a semi silly (But also possibly pragmatic, if we want to do this for more than simple 'fun') question... I wonder what it would take for projects like this, to take the video output and turn it into a (possibly not-visually-usable) jankhacked data output stream that could then be decoded?
I mean, there's a lot of hand-waving there (i.e. it would only be output which could complicate ease of using it practically) OTOH it might free up resources?
(I'm not experienced in this hardware level so I apologize if this idea is absolutely stupid/impractical.)
Not a silly question actually.
There's really clever ways you can get down to scratch that space-saving itch; I'm not knowledgeable about it either (I'm just really bad when it comes to analog signals) but if you really, really needed to shave off even more stuff; I reckon that the video console driver could possibly be reduced to something far more esoteric (That'd need signal processing to get tangible output of). But at that point, just use UART (Which is simple-enough already and should not really starve you out of much memory).