XRGB-3 giving me the poops

[humbug]

So using Game in for RGB-S

Now the part that is confusing me is the signals the XRGB3 requires in order to display its video correctly.

Looking at the jp21 pinout, it shows things wich i am not sure are needed on the XRGB3, such as AV select and stuff like that.

Im just using the same common ground for reg ground, blue ground, green ground, sync ground, audio ground etc... but im not too sure if thats correct.

I am hoping someone can post a pinout of the female game input that is needed for RGB only (i am not using audio)

Also is a coupling capicitor and 75Ohm resistor required for systems that dont already have it?

Cheers!

[Fudoh]

Looking at the jp21 pinout, it shows things wich i am not sure are needed on the XRGB3, such as AV select and stuff like that.

not needed on the XRGB-3. You just need R/G/B/Sync/GND/AudioL/R.

Im just using the same common ground for reg ground, blue ground, green ground, sync ground, audio ground etc... but im not too sure if thats correct.

yes, one GND line is enough. If the cable has different GNDs for Video and Audio you can use two.

Also is a coupling capicitor and 75Ohm resistor required for systems that dont already have it?

Depends on the system. If the stock RGB cable doesn't have any, you usually don't need any.

[humbug]

Thanks for the reply

well, i have a Japanese Sega Megadrive connected up to the XRGB... the picture looks pretty crappy.

My main problems are heavy vertical scan lines and the picture doesnt seem to be very sharp. I have it set to 220ohm, pixel mapping on, AFC on zero, drawing method field, ntsc DC set to auto, vsync lock off, B0 mode, Y/C filter auto, res 1440x900, adc 255, sharpness on 31 (looks super blurry lower than 7) and low pass filtering on...

what else should I change to get a flawless picture? I updated the firmware to english and the cpu firmare along with it i think... that was from the wiki site if i remember correctly...

another question I want to ask, for the purpose of sync on jp21, does the xrgb like the sync line or composite video better?

my system doesnt have coupling caps or resistors.

[Fudoh]

My main problems are heavy vertical scan lines

what are vertical scanlines ? Maybe you're using Composite Video for sync instead of real sync which produces those "jailbar effects" (?).

and the picture doesnt seem to be very sharp. I have it set to 220ohm, pixel mapping on, AFC on zero, drawing method
field, ntsc DC set to auto, vsync lock off, B0 mode, Y/C filter auto

pixel mapping on causes weird aspect ratios... Drawing Method has no effect and Y/C filter is just for the video inputs, not for RGB.

res 1440x900, adc 255, sharpness on 31 (looks super blurry lower than 7) and low pass filtering on...

With sharpness 31 you get a completely screwed picture full of ghosting and false sharpness.

what else should I change to get a flawless picture?

and you're using a RGB cable right now ?? I didn't get that from your posting.

Take a digicam photo of your screen and post it here.

[RGB32E]

My main problems are heavy vertical scan lines

what are vertical scanlines ? Maybe you're using Composite Video for sync instead of real sync which produces those "jailbar effects" (?).

and the picture doesnt seem to be very sharp. I have it set to 220ohm, pixel mapping on, AFC on zero, drawing method
field, ntsc DC set to auto, vsync lock off, B0 mode, Y/C filter auto

pixel mapping on causes weird aspect ratios... Drawing Method has no effect and Y/C filter is just for the video inputs, not for RGB.

res 1440x900, adc 255, sharpness on 31 (looks super blurry lower than 7) and low pass filtering on...

With sharpness 31 you get a completely screwed picture full of ghosting and false sharpness.

what else should I change to get a flawless picture?

and you're using a RGB cable right now ?? I didn't get that from your posting.

Take a digicam photo of your screen and post it here.

Yup, depending upon the Genesis system and the connected display config, you WILL get vertical stripes (alternating columns of pixels that are lighter/darker) when using composite video as sync!!!! I've tried using a sync stripping circuit on Genesis composite video, but in many cases the JBs persist!

A few things to remember when connecting a Genesis via RGB to the XRGB-3:
-Cap and resistor in series on R, G, and B
-Don't use composite video as sync
-Buffer CSYNC with a hex buffer
-Something isn't right if you have to use the 220 ohm setting... though I use the D2 RGB input whenever possible as it gives a sharper picture than the GAME input.

Have fun!

[humbug]

Thanks alot guys!

Yep, you guys nailed it. I am using composite for sync, and its giving me the gaolbar effect.

so pixel mapping isn't a true aspect ratio?

the sharpness when I have those settings didn't seem to give me artifacts like my other systems do.

and yep, im using the jp21 socket.

I'll be sure to take some pics when i get back home tonight.

I'll switch the sync and composite lines on my custom socket and I'll put those caps and resistors in the machine.
If that doesn't work, I'll look into the hex buffer.

I always wondered about the D2 socket vs game in, so I'll give that a try too!

Thanks guys!

[ZOM]

-Buffer CSYNC with a hex buffer

Wot!? Did you get rid of the jailbars from cSync with that? Care to elaborate on the circuit for it?
I still have a model 1 MD I modded ages ago and there's jailbars even after getting proper cSync...

@humbug, sorry for hijacking the thread - but I think this might help you too if you're still having those pesky bars after getting proper sync.

[humbug]

nah don't sweat it man

i need to know about the hex buffer circuit in order to build it anyway so im glad you asked

[humbug]

I tried switching composite vid and using propper sync on the jp21... it went from gaolbars to not working at all FFFUUU!

So i then hooked up the D in 2 RGB.

followed the pinout from the jap manual (jap skills came in handy ^^) and it worked first go... however i was forced to use RGBHV setting instead of RGBs because it was getting stuck on 45kHz instead of 15kHz... resulting in only the top half of the screen being used and squashing the picture into that...

So when I used the RGBHV instead, it was giving me bad warping at the top of the screen, so I had to set the AFC to about 4 or 5...

Now the picture is abit clearer but now im getting artifacts when I turn sharpness up when before i didn't when I used 220Ohm setting on the jp21 input. the image is a tiny bit shaky/jittery on the horizontal too.

I am also still getting faint gaolbars... its really noticable on rich blue colours...

I am still to put the cap and resistor on the RGB lines and buffer on the sync line... will this fix my problems?

[ZOM]

I tried switching composite vid and using propper sync on the jp21... it went from gaolbars to not working at all FFFUUU!

Did you connect the CXA1145's cSync to the Megadrive connector's sync-pin? I had to do this to mine, since the internal wiring was wrong.

[humbug]

oh really!

well, i havnt opened the megadrive yet... but i suppose i cant rule that out as impossible...

could d in 2 rgb still work without sync? does the md produce Hsync and Vsync internaly? if so, it seems like a good idea to use that right?

[humbug]

what would happen if i sync on composite video on the MD?

would anyone know if that would do bad things if I was to have the Sega32x sync of composite too?