Inklings: a tumblelog

A simple universal 800×600 VGA signal generation circuit

Just curious as to what would be involved in generating a VGA (though 800×600 is actually SVGA) signal.

I was reading up on the Motorola 6845 CRTC to see how you’d drive a display. That only tells you what you should be rendering at any given moment, and between the VGA signal generation circuitry and the 6845 (though a HD6445 CRTC-II might be more appropriate), you’d need a bit of glue logic to take the output of the CRTC, look up the character and palette data, then translate that to pixel data based on a character and palette ROM lookup.

All this is way beyond me right now though! Still, at some point, building something like that (maybe some kind of VGA terminal) might be a fun exercise when I’ve some kind of actual competency in this stuff.