mega drive (Y Pb Pr) or (VGA) mod ?

hi guys
i hop you understand me, because my English bad

I'm tired of attempts for get (Y Pb Pr) or (VGA) mod diagrams for mega drive because i lost my old TV and i connect my mega drive to LED/LCD TV but the picture so bad.

 

They don't support that. Only RGB, S video (with modification), and composite out. Need an upscaler to get VGA or component (Y Pb Pr) out. This one is best for getting RGB converted to VGA. Shop around. You might find a cheaper solution.

The Sony video encoder chip on the Genesis and Mega Drives only supported amplifying the RGB, S video, and composite. Component (Y Pb PR) didn't come about until later and VGA obviously couldn't be implemented due to hardware limitations and price.

 

Get an RGB cable for your SMD and either use a RGB to component video transcoder. This is cheaper - cable is not too pricey and a transcoder shouldn't be more than $50 I think (haven't looked recently though). That's what I'm doing these days, the output looks stunning.

Alternatively you can use something like the XRGB Mini that Yakumo sells. Looks like an amazing piece of kit and will upscale to 1080p via HDMI. If I wasn't gaming on a CRT that's I'd be using.

Good luck!

 

After the patience of a large shipment arrived (RGB VGA converter v3.0) I have added Scart socket and LM1881N for Cync then i got the problem with screen jumping

see YouTube please:-

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Make absolutely sure you're giving it enough power. I was even using a wallwart ac adaptor rated at considerably higher than the 2A required for the board, however it must have been a poor quality adaptor because it wasn't enough. When I tried with a PC power supply, my screen stopped jumping. Now I'm using an arcade power supply for the +5V and it works great.

Once you get that converter working, I highly recommend adding a scan line generator as well, it looks so much better on an LCD!

Hope that helps!

 

i used good power supply and i also used 5+ from my PC its same problem and about (scan line generator) i already built one.
i used this diagram from http://www.mmmonkey.co.uk

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try to adjust rgb pots on converter, sometimes rgb levels are too much.

 

Please don't recommend the GBS, they're horrible, and mine simply refused to display a synced image when Sonic 2 (from memory) was in 2 player mode.
The quality was hardly better than composite, and obviously worse than S-Video.
In no way is the GBS "one of the best" its one of the cheapest, and that's about it...

The GBS's I've measured need less than 500ma, if you had issues with a 2amp PSU, there was something seriously wrong with it to begin with...

If you're wanting to display the RGB output from a Mega Drive, Amiga, or any other 15Khz game console or computer, I would highly recommend an RGB scart to ybpbr adapter.
However! Not all tv's will accept ypbpr in this format...
But! Because these adapters simply add/subtract the video r/g/b video signals to/from each other, you end up with an image that's almost as good, if not just as good as RGB scart...

If you have any questions, feel free to ask!

 

I have tried not successful

 

i test my PlayStation models 7502,9002,5502 and 7500 no signal and green screen 1 sec

 

Help please

 

check you got the wiring all correct the first time i did this with mine i had it wired wrong, not sure how i got it wrong but i did, Red Green Blue Sync and make sure all the grounds are wired up sync should be going through the LM1881 and into the Horzontal sync input

edit: also try the "auto" button on the GBS8220, hold it for a few seconds and release

 

I checked all wiring are correct and ground too
and about "auto" button, I set my MD2 to PAL50hz and i press the auto button 3 sec hold and release, the led going flashing and the screen stop jumping, after led stop flashing the screen back jumping, with PAL60hz nothing happen still screen green and wavy

btw: i used capacitor 220uf and 75ohm resistor before GBS8220 because i don't using an official RGB cable. is that the reason ?

 

I beleive 75 ohm resistors are not neccesary, The Board already has them. I also experience same using v3 Board After a year it worked with regulated power supply, what Version Board do you have.

 

Do you have any clear pictures of how you connected the GBS to the Sega?

See post number 8 in this thread for my opinion of the GBS (it took a day for the post to be approved)

Here's a video of what I'm talking about, It worked "ok" in single player mode, but two player mode must have changed the screen resolution or something, and it just failed to work properly.


My two GBS's are now just sitting on a shelf. To me, they aren't worth the time and effort to get them to work "ok"

This was in 50Hz, but I couldn't adjust the gbs to make it full screen, as that would simply result in the gbs crashing...

 

GBS 8220 V3.0
and my megadrive2 Ver VA4 PAL

 

after i connect the #3 on LM1881 to V on GBS the screen stop jumping but after afew mint the screen lock like your youtube and after afew more mint the screen back jumping. i cheanged the mode on GBS from RGBS to RGBVH mod the screen not jumping or flicking but the signal wake and color bad

I thought that because of the resistors and capacitors in RGB cable, i removed them and adjust RGB but no thing happen

 

the colours probably need to be adjusted via the 3 yellow pots near where the input is one is for red one for green and one for blue. tweak them until the colours look right. i think yours is wired up slightly different than mine

 

I have tried with 3 yellow pots but no thing happen and about wiring look blow picture
note: Do not take into consideration this picture It's different from what is now.see the only connctions






high resolution

http://imageshack.com/a/img513/8/ksw7.jpg

 

values i used 680k resistor where you have a 200k

http://www.mmmonkey.co.uk/console/other/rgb2vga.htm is what i roughly followed if you scroll down the page to "sync cleaner update" it shows how its been added to the GBS 8220 a trace needs to be cut or it will still use the non stripped sync

also http://gamesx.com/wiki/doku.php?id=av:lm1881&s[]=lm1881

the circuit i used for the sync stripper is here http://www.mmmonkey.co.uk/composite-sync-stripper-lm1881/ << scroll down to the alternative version I'll put a pic and video up later when i get round to it