ShadowofBob wrote:I was reading through the Wiki this evening and noticed the bit about using TTL level c-sync needing a 470ohm resistor or similar if used through the SCART input. Is that still the case?
http://junkerhq.net/xrgb/index.php/OSSC ... B-SCART.29
Just wondering as all my consoles I plan to use have csync SCART cables that seem to work fine on a GBS8200 and my projector via a SCART to VGA(sync on 13) cable. If it's better/safer I can just use the SCART to VGA cable on the VGA input, but would prefer to take advantage of the LPF.
*edit* Looked into this a bit more on my own and from what I've found the maker of my cables (retro_console_accessories) most likely already has these modifications done in the cables. I'll test them myself and ask her to be sure though.
It it still the case. The fact is that you should never connect TTL level c-sync directly to a 75ohm terminated video/sync input, be it OSSC, Framemeister, TV etc. It will certainly work in most cases, but you're overloading the IC inside the console which produces the sync signal - not a good thing in a long run. With 75ohm termination, the high-impedance TTL sync signal won't generally reach such high voltage that it'd damage the sink - from sources like MD it won't even be high enough for valid sync - I'm just stressing that one should be aware of the possible risks when making such connections.
paulb_nl wrote:I have been wrapping my head around this but my brain does not have enough CPU and RAM
. Would something like this work to get a valid 720p signal?
Set the output rate to 750/262. We need to input only 750/3 = 250 lines so start output after waiting for (262 - 250) / 2 = 6 input blanking lines.
Because the output is slightly slower there will need to be 250 - (250 / 262 * 250) = ~12 lines buffered. When the output is finished the input is already past the 6 first blanking lines of the next frame so it is caught up.
In principle, yes. In practice, this might need an external programmable PLL since such ratios may not be acceptable with low/medium-end FPGA PLLs.
akumajo wrote:Another feature that I would like to see is a black frame insertion feature for 120Hz displays, but it would probably require a frame buffer ?!
Yes, it'd require it. A bit off topic but I just read a
review of Eizo FS2735. The specs looked promising not only for PC gamers, but also for those playing console games due to backlight strobing support in 60, 100, 120 and 144Hz modes. It was quite a disappointment to read that 60Hz mode is botched with dual strobing, which causes artifacts etc.
I really hoped Eizo would have offered real 60Hz strobing regardless of the flicker, since that would have been great for console gamers.
It seems there will be a small amount of assembly required to fix the LCD on, but I should be able to find someone local that can do that without breaking the bank.
