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Genesis RGB Question
sonic412781 - Jun 26, 2006
  sonic412781 Jun 26, 2006
I've heard some people say they've hooked up their Genesis system to a RGB monitor. I want to do that but I don't know of which monitors the Genesis will work with. I have a model 2 Genesis (US NTSC); anyone know which monitors have the correct VSync for the Genesis' video signals? and if so, what parts would I need to get them hooked up properly? (remember I'm in USA, so there are extremely few (if any) RGB-equipped TVs and we don't use SCART connectors either)

Also, any info on how to make a circuit to convert RGB signals into an S-Video signal would be greatly appreciated.

 ExCyber Jun 27, 2006
The original NEC Multisync series (like from 1984 or so) can handle a low enough hsync (vsync isn't the issue) to work with game consoles. I never tried it though. You'd have to make a custom cable; the Multisyncs use a 9-pin connector (same as you'd find on a PC-style serial cable), and for the Genesis side it uses either a full-size DIN or mini-DIN (don't recall the number of pins).

As for video encoding, there are some circuits described in links from this page..., but if memory serves at least a few of them are based around an obsolete Motorola chip. You might have better luck with datasheets and/or appnotes from Analog Devices..., whose chips are pretty readily available from several distributors (they seem to have an online store as well). Their video encoders can be found here... (you want the ones at the top that say "n/a" for the number of DACs; ones with a number there are for producing NTSC/PAL output from a digital stream).

Hope this helps.

 Mask of Destiny Jun 27, 2006
Anything advertised as an Amiga monitor should work.

 sonic412781 Jul 22, 2006
I recently purchased a Commodore 1084S monitor, which I was informed was able to display the RGB signals that the Sega Genesis outputs; however, none of the pinout diagrams for Genesis explains whether the Sync line (pin 5) is HSync, VSync, or CSync, or none of the above (perhaps it's a clock signal used to synchronize the processors?). According to the pinout diagrams for the 1084S, there is a pin for HSync and one for VSync. I assume I would need to have signals applied to both pins, so my question now is this: What kind of signal is the Genesis' Sync line, and how would I get the complete signal to display properly on the 1084S monitor?

Here is the pinout for the 1084S, if it helps:

-----6-----

1---------5

------------

-2-------4-

-----3-----

1-Blue

2-Red

3-GND

4-HSync

5-Green

6-VSync

Maybe I could just wire up a LM1881 chip to the composite video pin (4); I wouldn't even need to worry about pin 5 then, right?

 sonic412781 Jul 22, 2006

  
	
	

		
		

			You might have better luck with datasheets and/or appnotes from Analog Devices, whose chips are pretty readily available from several distributors (they seem to have an online store as well). Their video encoders can be found here (you want the ones at the top that say "n/a" for the number of DACs; ones with a number there are for producing NTSC/PAL output from a digital stream).


What about AD724? I'm not that good at circuit design; would anyone be willing to help me come up with like a plug-in module for the Genesis, one that would plug into the AV OUT port, so that no internal modification would be needed? Perhaps something like:

Genesis AV OUT port}---{AD724 circuit}----------------------{TV S/Video

(the "-------" being AV cable)