Genesis CDX RGB

[Segasonicfan]

Hey guys,
 I'm almost done with my CDX portable masterpiece but as one final addition to the system I would love to give it an RGB output.  I know very little about RGB, just what I have read here on GameSX.  I got the A/V pinout from the site (same as model 2 Genesis) but I need Chroma and Luma, right?  I can't find a page here that shows me where I can wire Chroma and Luma from my Genesis 2 (only Genesis 3...and I'm not sure if that's the same).  If anyone could just tell me where I get those to lines from (and if I need to add resistance or anything) that would be really appreciated

Also, I plan on using my flat screen Sony Computer monitor for RGB.  Should that work?  It has a 15 pin output...I figure that should be more than enough for RGB.

If anyone could tell me anythign related to these questions that would be great...sorry for being such an RGB N00B!

-Segasonicfan

[Aidan]

Ok!  RGB stands for the colours Red, Green and Blue. For displays like TV and monitors, these are the primary colours. As both the display and the console work internally with RGB, if you connect them together with RGB you tend to get a better picture, as the RGB signal does not have to be converted to something else to send down a wire, and then converted back again when it gets to the other end. For RGB you do not need Chroma or Luma at all!

However, you need to check that your Sony monitor can accept signals at such low rate. Most monitors are not designed to handle signals that are as low quality as TV video signals! Instead, they're designed to handle higher frequency signals that computers put out. I can't remember the specs for the video signal right now, but I'm hoping Lawrence or other helpful person can provide the sync rate information.

Otherwise, you'll end up having to purchase an upconverter that can take a video signal and convert it to a VGA signal!

[Segasonicfan]

Hey thanks for your help  I reread the Genesis 3 RGB mod and saw that Chroma and Luma are for S-Video...which is something I don't really need from my CDX (and I don't think there's a mod for that anyway).  I finished the RGB output on my CDX and it's really nice...now all I need is an RGB screen.

Unfortunately my Sony monitor doesn't have any specs on the back, it simply says TFT LCD Computer Monitor.  If I opened it up (which I have done before to repair it) do you think there is some way to tell if it would work with my CDX for RGB?  If not, I have an HDTV-would that be RGB compatible?

Thanks again for all your help!

-Segasonicfan

[Segasonicfan]

Hey, I found a helpful ebay auction with all the information about my Sony monitor.  It's over here:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...ssPageName=WDVW

It says it's capable of RGB at 0.7 volts.  That should be enough since my CDX output RGB voltage is around 3 volts  It's a D-SUB 15 connector though, and i have NO CLUE which lines are the RGB lines...I also couldn't find a D-SUB 15 connector at Radio Shack...any suggestions? :-(

-Segasonicfan

[Aidan]

Generally if you can find the manual or the specifications for it (perhaps online?), then you should be able to find what horizontal or vertical refresh rates it will support.

It needs to be able to support interlaced video at a horizontal refresh rate of 15.75kHz and a vertical refresh rate of 60Hz for NTSC. For PAL, it'd need to handle a horizontal rate of 15.625KHz and a vertical rate of 50Hz.

I have no idea about your HDTV, as I've no clue to what inputs it might support!

[Segasonicfan]

on the site I mentioned (since I don't have the manual, I was given the monitor as a gift) it says:  

Horizontal frequency: 28 to 64 kHz
Vertical frequency: 48 to 75 kHz

So it would work for the vertical rate but probably not for the horizontal, right? :-(

Please let me know, thanks for your help!!!

-Segasonicfan

[NFG]

So it would work for the vertical rate but probably not for the horizontal, right? :-(

You're absolutely correct.

[Segasonicfan]

Yup, I just tested it and the monitor said 'out of scan range'  it was pretty hard to test too, b/c the monitor automatically turns off when unplugged.  I didn't realize it needed the ground signal from the CDX in addition to the RGB lines, but that would make perfect sense since you need the negative charge.  Took me awhile to find a monitor pinout too, but alas I did not prevail :-(  Does anyone have any monitor suggestions that might work?

Thanks for the help guys, sorry I'm so new at the RGB thing.

-Segasonicfan

[Endymion]

Commodore 1084 monitors work well and are dirt cheap. They're very small (13") but I think there are some 17 or 20 inch models--never seen one though.

The Sony PVM models work great and have a DB25 connector, very easy to work with when you're starting out. Most of them are very large and very heavy.  Mine is the PVM 2570, 27 inch screen (not 25) and it's great, it can take a video sync instead of a composite sync so you don't have to worry about stripping it. (i.e. it's easy to work with.)

There is a Sony GVM which is 20 inches and can work with a VGA signal as well as a video game's RGB signal, trouble is the VGA resolution is only 800 lines (which is grannyvision on a computer screen that large), but if you can live with a computer resolution that low that's another one to get, it also uses the DB25, easy to get into.

Then there is the NEC CM-2791 which someone has had on ebay for the past couple of months. The one I got is in great condition and the screen itself is even nicer. It needs to have a straight composite sync (not a video signal) so you have some extra work to do, but I prefer it over my PVM because the screen just looks so nice.

[Segasonicfan]

Hey thaks for your help  I think I'm gonne go ahead and pick up a Commodore or Amiga monitor since that NEC one seems to be pretty expensive (if I'm going to pay that much for a monitor i might as well get XRGB-2, yknow?)  

I looked at all the outputs on my TV and one of them is Component video.  It has the red,blue,green,audio L, and audio R inputs but no sync :/  Also, they arent labelled R,G, and B.  They're labelled Pa,Pb, and Y (for green).  Is this something other than an RGB connection?  

Also, does anyone know if there are any RGB lines in DIV-HDTV?  cause my TV has that too.

Thanks for all t he help, I really appreciate it guys

-Segasonicfan

[NFG]

I looked at all the outputs on my TV and one of them is Component video. <...>  Is this something other than an RGB connection?

That's right, it's for component video.

[Endymion]

I think I'm gonne go ahead and pick up a Commodore or Amiga monitor since that NEC one seems to be pretty expensive (if I'm going to pay that much for a monitor i might as well get XRGB-2, yknow?)

In my world, 109 bucks for a 27 inch RGB monitor is incredibly cheap--shipping set me back 65 dollars and it's still cheap. The Sony PVM 2570 I got in 1998 I paid 400 for and it is the same size, not in as good condition as the NEC.

[atom]

If you can find an old applecolor monitor from a pawn shop your all set. They have beautiful picture but cant handle resolutions above 640 x 400 (no not 480).
Unless your pawnshop sucks it will be less then 10 bucks.

[Segasonicfan]

Thanks for the tips guys :-)  I think I'm going to wait to get an XRGB-2 though, cause I have a $1300 Sony flat screeen monitor (which I'm using now) that i would LOVE to play RGB video games on.  And spending $174 with shipping for an NEC monitor just doesn't make sense when I can buy an XRGB-2 for $200 and I can use the monitors I already have.  Thanks for all your help, even if I can't play RGB now, at least I got the output all built into my CDX and I'll have the system done this week with pics!!

-Segasonicfan

[D-Lite]

Question I have is what is the video encoder on the CDX?  Is it a Sony CXA chip?

I'd love to slap S-Video in there without adding an IC to encode for it.  

[Segasonicfan]

I would like to know how to add S-video myself.  It doesn't have a Sony chip though, that's only in the Genesis 3.  And if you're thinking about opening up your CDX to add S-video (or any other mods, including the import one which I can tell you how to do), make sure you know what you're doing.  This guy is a REAL pain to open, and when you break one you feel REALLY bad since they're holding a $100+ value these days.  Let me know if you want any tips ;-)

-Segasonicfan

[NFG]

Does the CDX not use a CXA chip like the rest of the Genesis line?  The only ones that use a different chip are the WonderMegas, which use a Fujitsu part.  I didn't think the CDX used it as well.

[Segasonicfan]

I could not find any chips labelled CXA inside the CDX.  if you give me a picture of what it looks like, I can scan the boards better.  I have 2 broken CDX PCBs so I can look for chips on them easily.

-Segasonicfanh

[NFG]

What are you needing pictures for?  It's a chip.  A chip like all the rest, but i'll say 'CXA<something>' on it.  =P

Here's the one from a Genesis3:



The CDX one will likely look similar.

[D-Lite]

I really hope it has a CXA....  

Does the X'Eye at least have RGB?  It does, correct?  At least then I can use a separate encoder to do S-Video.

Also, Lawrence, not all Genny's have Sony chips as far as I can tell.  Earlier Genesis 2 models have no Sony chips at all.  I haven't looked too hard yet, but I can't figure out which chip is for video and if I can pull Y and C off of it.

[D-Lite]

And Lawrence, if the Wondermega didn't have a CXA chip, then what's this page:

http://www.gamesx.com/grafx/wondermega.jpg

[Segasonicfan]

i KNOW it doesn't have the CXA chip...I was asking for a pic of the other kind of chip that you mentioned the Wondermega's having.  I know what the CXA looks like, it doesn't have it.

-Segasonicfan

[D-Lite]

i KNOW it doesn't have the CXA chip...I was asking for a pic of the other kind of chip that you mentioned the Wondermega's having.  I know what the CXA looks like, it doesn't have it.

-Segasonicfan

Thing is, I would bet it's an S-Video compatible chip since the Jp Wondermega has S-Video out.  Unless of course they had a different board revision for the US X'Eye, but that seems odd to me.

Wondermegas/X'Eyes have RGB?

[Endymion]

SSF: I won't tell you how to spend your own money, after all, it is your money. But the thing about an RGB monitor--any RGB monitor, assuming it's not defective--is that it is going to look a lot nicer with broadcast RGB than the same broadcast RGB upscanned to VGA. The XRGB2 is a nice stopgap, but I don't know a single RGB monitor owner who would prefer games another way. (Except for maybe component, and it would be even more questionable using an XRGB2 to upscan to VGA then transcode to component for HDTV--although there are such lunatics out there.)
The thing that's nice about a good RGB monitor is that they can be large, and there are a lot of them out there. Having a large screen is, I think we can all agree, always a great thing for your games, and it's not too many computers that are paired with anything bigger than, or even as big as, a 20 inch monitor. (Mine is but again, lunatics.) The screen size is really the best thing going for playing games on a (normal) television, and not ordinarily an attribute of monitors; but with a good arcade or video monitor suitable for RGB, you gain the benefit of the size along with the purity of the colour. I would really have to be cramped for space down to my heiny practically before I would sacrifice either of my two  27" RGB screens (or my 14" Commodore) for an XRGB2 with my computer monitor. Use the knowledge of that preference wisely.

Lawrence (and everybody else): I just opened up a Genesis 2, and it looks like it is actually a "later" model (the board is stamped 25 AUG 1994), and it doesn't have a CXA chip. It does have a chip that appears to be the same as the one in the Wondermega2, the Fujitsu MB3514. It is the same size with the same number of pins, the pin-legs are equally long and laying across the board. So I'd guess this is serving whatever purpose the CXA does in other models. (RGB amp, s-video, etc. etc.)

Does anybody have the wiring info on this one, or would it be the same as the CXA? It does look identical, except for the markings. I would kind of like to destroy this console--I bought it off ebay on the cheap for this very purpose (RGB amp) and it STINKS, smells like the guy wiped his ass with it then used it for a cigar ashtray. However, I feel kinda bad killing a Sega console if there's nothing to come from it. I googled around for the wiring data on it and only found this.

Could it be an RGB mod?

[Endymion]

Hi there.

I have a history of solving my own problems and using Lawrence's website to journal my progress. It's wonderful to feel really smart and really stupid at the same time.

Much to the benefit of everyone. (Nevermind the guy supplying the chip using Lawrence's pinouts for the system.)

I guess if this chip uses the same resistors/capacitors as the CXA then I can pull this thing off and get to work. (Then fumigate my apartment, I swear this console stinks.)

[D-Lite]

Does anybody have the wiring info on this one, or would it be the same as the CXA? It does look identical, except for the markings. I would kind of like to destroy this console--I bought it off ebay on the cheap for this very purpose (RGB amp) and it STINKS, smells like the guy wiped his ass with it then used it for a cigar ashtray. However, I feel kinda bad killing a Sega console if there's nothing to come from it. I googled around for the wiring data on it and only found this.

Could it be an RGB mod?

I checked that WM2 page and found another on that site with a pic of the chip pinout:
http://www1-1.kcn.ne.jp/~sarming/handa/wm2_pin.html

That's what I'm hoping to find, Y and C right off the chip for the X'Eye and maybe the Gen 2.

EDIT:
Found the .pdf for the MB3514!!!!
http://www.fulcrum.ru/Read/CDROMs/FUJITSU/...eds/e428020.pdf

[NFG]

As far as I'm aware ALL genesis units have Sony CXA encoders, but then I've only opened maybe 50 of the things, not a wide sampling rate for a system that sold in the bazillions.

The X'Eye (and all the Wondermegas) never had RGB output available outside the system; this was a drawback when the 32X was released, and JVC was at one time offering a free modification to the system to give it an RGB port.

[Endymion]

Good on you mate! Looks like the pin diagram is the same as what's on the other site (already spotted it, we posted simultaneously), if it's got any caps/resistors listed we're in business.

[D-Lite]

As far as I'm aware ALL genesis units have Sony CXA encoders, but then I've only opened maybe 50 of the things, not a wide sampling rate for a system that sold in the bazillions.

The X'Eye (and all the Wondermegas) never had RGB output available outside the system; this was a drawback when the 32X was released, and JVC was at one time offering a free modification to the system to give it an RGB port.

But the Wondermega and X'Eye have the Fujitsu MB3514 chip that is both RGB and S-Video capable, correct?  Seems so based on the link on your site and also on the web.

BTW, I just opened a Genesis 2 last night and ain't no Sony CXA visible anywhere, neither DIP nor SMT.  I haven't traced the RGB lines back to a chip yet, but will do so tonight.

[D-Lite]

Good on you mate! Looks like the pin diagram is the same as what's on the other site (already spotted it, we posted simultaneously), if it's got any caps/resistors listed we're in business.

Caps and resistors?!  Who cares, if the chip is there and is capable, I'll add any of those caps/res necessary!  I have a huge pile from all my Turbo Grafx/Duo mods and superguns.....

EDIT:
The Y and C output for the MB3514 seem different than the CXA series chips, with a bandpass filter and mixer in place including use of the Y out AND Y in lines.  I'm really looking forward to getting my first X'Eye tomorrow and checking out this mod!

[NFG]

And Lawrence, if the Wondermega didn't have a CXA chip, then what's this page:

http://www.gamesx.com/grafx/wondermega.jpg

That's a page written by someone else for a machine I've never owned (The X'Eye in this case, which could have a different chip than the WonderMega; there's a lot of other changes to this machine like the removal of the IR port, so why not change the encoder while you're there?  Another explanation:  Since the Sony + Fuji chips are pin-compatible perhaps he used the CXA designation without realizing it wasn't a CXA chip?

The Y and C output for the MB3514 seem different than the CXA series chips

It's been a while but I remember thinking these chips were identical replacement units, pin compatible with each other, tho I may be confusing it with the definitely-identical ITRI/ERSO ES71145.

Pulling S-video from the CXA1145 is a pain in the ass, as the chip was not designed for this purpose.  I point to the NEOGEO S-video mods as proof of this, they go through mad extremes to get decent Svideo from this chip (though it could be said neo fans go through mad extremes, full stop).  

[D-Lite]

I'm currently doing a Gen 1 mod using the Neo AES S-Video plans.  Not too big a pain, but definitely more work.

On a different note, the just checked out the Genny 2 I mentioned earlier that has no CXA chip in it.  The video encoder is a Samsung KA2195D (datasheet found here: http://www.alldatasheet.com/datasheet-pdf/...G/KA2195D.html).  This cheap is truly a cheap ass.  It's essentially a CXA1x45 without either Y or C.  Pretty much just functions as an RGB amp as far as I can tell.  Board revision VA1, produced in Taiwan for those who'd like to know (I plan on starting a list of locations, production dates, board revs, and chips...)

Hope that sheds some light.

[RM2]

I have a Genesis 2 with board revision VA2.3 uses a Samsung KA2195D encoder, which is pin compatible with a CXA1645, except it's NTSC only, and it has no S-Video; those pins on the chip do nothing at all. I think the unused traces are still there so some VA2.3s might have CXAs instead.

Of course a VA2.3 uses a 315-5685 208-pin custom chip, which does NOT have the pinout shown on Gamesx, even though that page claims all 315-xxxx chips are the same. Do that mod on a 5685 and you'll be left with a piece of worthless junk. Good thing I checked whether the pins in question were even connected to 5V or GND before doing anything.

I pointed that out in this message:
http://nfg.2y.net/forum/index.php?showtopic=799
over a month ago with no response, and the Gamesx page is still wrong now. Wonder how many machines have been ruined because of that page?

A VA4 revision Genesis 2, the one with the smaller board, doesn't even have a 208-pin chip but has a 200-pin chip instead, still with a 315-xxxx number. That version has SMT jumpers going back to the design of the original Genesis, and Mike G has the info on those.

[NFG]

I pointed that out [...] over a month ago with no response, and the Gamesx page is still wrong now. Wonder how many machines have been ruined because of that page?

It's fixed now.  As for how many were damaged, my guess is zero 'cause no one's mentioned it to me before.

Thanks for pointing that out.

[Segasonicfan]

I just checked the CDX and it does have the Famitsu chip...thanks guys!  I'm going to check the S-Video lines on it now and post here later.  

-Segasonicfan

[Segasonicfan]

I checked the S-Video from the chip...my TV did show video that looked great except there were vertical lines running throuhg all the video.  I didn't add any resistance or capacitors to the S-video, could that be the reason for the lines?


-Segasonicfan

[D-Lite]

I checked the S-Video from the chip...my TV did show video that looked great except there were vertical lines running throuhg all the video.  I didn't add any resistance or capacitors to the S-video, could that be the reason for the lines?


-Segasonicfan

Part of the reason.

The MB3514 chip seems to be a CXA1145 clone, not 1645.  All these will give you a picture, but to varying degrees.  The 1645 is the closest to a perfect signal right off the chip and only requires a couple of 220 uF caps and 75 ohm resistors.  Looks nice.

The 1145 and 3514 will take a bit more effort.  A quick and dirty solution is the mod I've seen using a 220 uF cap on pin 16 and 100 uF cap on pin 15.  This works and the pic looks good, but it's not the most accurate pic you can get.  To truly get the best quality, do the Neo Geo AES style mod as found on the www.neogeousa.com site.  Requires a couple of other parts but the pic is much nicer overall and works well.  Did both types of mods last night and I'll tell ya, the difference is noticable.  I'll be posting pics of the screens in the near future at my site (www.aloofhosting.com/dragsy/) where I have my Turbo mod pics currently.

Oh, and vertical lines are usually due to interference from your ground line.  Ground the video to someplace where nothing else is grounded.

[Segasonicfan]

Thanks for the info.  Yeah, I think the lines are to capacitance and resistance becuase they are not moving at all indicating any kind of grounding problem.  Plus, I grounded them to the main video ground.  As for the mod you mentioned, I couldn't find it on the Neo Geo site, only the Sony CXA chip S-Video mod.  I would love to have instructions on how to do the best S-Video mod for the MB chip.  I'd like to see those pics you have too

-Segasonicfan

[D-Lite]

Thanks for the info.  Yeah, I think the lines are to capacitance and resistance becuase they are not moving at all indicating any kind of grounding problem.  Plus, I grounded them to the main video ground.  As for the mod you mentioned, I couldn't find it on the Neo Geo site, only the Sony CXA chip S-Video mod.  I would love to have instructions on how to do the best S-Video mod for the MB chip.  I'd like to see those pics you have too

-Segasonicfan

CXA1145 = MB3514

same mod

[Endymion]

Drat, that mostly sucks. If the Fujitsu were like the 1645 it would be a lot easier going, no way I am going through all that trouble (through neogeousa's mod) just for s-video. Now on to the quest to find as many 1645's as I can. What systems were outfitted with these? Saturn, (some) Genesis, Playstation 1?