The Executive Summary
640x480 Video @ 8 bit color from a serial protocol that any Maker's parts can speak.
The Engineer's Report
As there are a number of interesting display-less dev boards and embedded linux products on the market nowadays (not to mention the 2 PogoPlugs and the Intel Galileo in my own parts bin), I set out to find a solution for getting reasonable video out of the world's collection of headless parts.
VGAtonic is my effort to make said headless parts connect to the displays people already have lying around - monitors with VGA input, and TVs with their anachronistic NTSC RCA jacks.
Our goals are modest - 640x480 is still the fallback, worst case resolution for lots of applications - so we'll target VGA's original 640x480 spec. Technically, the original VGA asked for just 4 bit color (read: 16 colors), but as an analog protocol we'll double the number of bits to 8 to get 256 colors. NTSC is still undecided, but in our tests we've been producing 16 colors and 16 brightnesses: 256 colors the hard way.
For the brains, we'll be using a 4MBit ISSI IS61LV5128AL-10 with a Xilinx XC95144XL CPLD providing the brawn and the timing. Our first reference design, a roughly 3"x3" PCB, was already released, and we decided to use a programmable oscillator (Linear Technology's LTC6903) and a microcontroller (Atmel's ATTiny 2313a) for board support and experimentation. If we do another design, we'll try to tighten it up and actually target an interesting size.
Oh, and we're going to do it all with a BOM of roughly $23-$32 a board.