fagin wrote:
The problem with the HDFURY2 output working effectively with the SLG is the sync polarity, plain and simple.
HDFURY or HDFURY gamer edition output the correct sync and work. HDFURY3 will output the correct sync if you change the dip sw setting on the HD3 to suit.
If this device relies on a specific polarity, the issue will be the same.
If the only difference is the sync polarity (short high pulse on HSYNC, at rest is low, rather than the more common short low pulse on HSYNC and at rest is high) then that wouldn't cause the problems described, for either scanline generator. Both flip flops only care about a single transition, from high or low, or perhaps from low to high. It doesn't care about the other opposite transition. Whether the HSYNC was a short high pulse or a short low pulse, there'd only be one of the triggering transitions per horizontal line. (I guess this is the long way of saying that niether device is relying on a specific polarity of the HSYNC.)
I still believe based on the description that it's a problem with an odd number of HSYNC pulses per frame. If this schematic is accurate:
http://nfggames.com/forum2/index.php?to ... 0#msg30650, then there is no reset of the flip flop during the VSYNC; it will alternate every HSYNC pulse. If it didn't reset on VSYNC, and the source was giving an odd number of HSYNCs per frame, then on the first frame it would darken lines 1, 3, 5, 7..... and the next frame would be 2, 4, 6, 8.... and then 1, 3, 5, 7..... on an on, alternated each frame. Mine resets on VSYNC.
I'll be borrowing SGGG2's HD Fury 2 shortly, and will be able to give a better answer once I get it under an oscope, but Im more and more confident that this is the problem seen with the HD Fury 2 + SLG3000, and that mine will work fine with it without modification. I'll definitely post up when I have it in front of me.