I'll try to keep this thread updated more though with progress reports. Here is what is on the agenda for the next couple of weeks:
-- Expanding the line buffers to 16bit. I've been meaning to do this for quite a while, as my original design was built around a color depth of 8bits to keep the proof of concept phase simple. Color depth of 16bits is needed to handle systems like Capcom CPS-1&2, Neo Geo MVS, and consoles with 16bit color. I'm already using 8-bits per channel ADCs so I don't have to upgrade that section.
-- Fixing the sync fill circuit. The VGA horizontal sync is derived from and locked to the source sync, however during the VBLANK interval there will be gap in the input signal. The sync fill circuit insures the VGA Hsync doesn't drift before the first line of the next source frame starts. Right now the first line of each frame has a tendency to be just a bit irregular, which doesn't bother most CRTs (they are generally forgiving) but causes distortion of the top line for the LCDs I have tested with. So I need to improve the sync fill to eliminate the slop in the signal lock.
I'll keep posting tech updates, I know the details don't matter to most beyond system compatibility, but it beats the familiar refrain of "still working on it"
![Wink ;)](./images/smilies/icon_wink.gif)