We love old video games, but we hate the way analog interlaced video looks on our new LCD monitors. [Michael] feels the same way, so heís created NeoVGA, A Neo Geo Line Doubler in VHDL. Neo Geo, like many classic consoles, didnít use the full resolution of an analog TV. In NTSC mode, it ran at 320◊224 pixels. PAL users got an extra 32 vertical pixels for 320◊256 pixels. The system ran with an approximately 15kHz horizontal sync and ~60Hz vertical sync.
This is not exactly a VGA compatible signal, so it would be relegated to composite or S-Video capable displays. The signals looked pretty good on a CRT, but on an LCD, they tend to look crummy. Modern LCDs donít natively handle interlaced and/or low resolution input signals. The TVís controller performs the magic of buffering, interpolating, and transforming the input signal to be compatible with the LCD panel. As [Michael] explains, most of these algorithms are optimized for TV video signals with lots of motion. They perform poorly on static high contrast images such as the background of a fighting game. TV controllers also add lag to the signal chain. Not much of a problem when watching movies, but itís a big problem when youíre trying to pull off that triple hit combo.

http://hackaday.com/2014/05/20/neo-g...-line-doubled/