gcvideo - Open source GameCube component cable solution

I've seen a few of those too, and the PCB mount sockets are likely available somewhere, but I'm worried that I won't be able to get a bulk load of them at a good price.

Strangely, the pre-made RGB SCART cables for the Saturn seem a fair bit cheaper than the MD 2 cables though?

(I actually had it the other way around originally, but then edited the post. lol)

I thought it made more sense to have Luma on the "Composite" pin, because then it would at least still give a B/W image if people had it plugged into Composite if the switch was set wrong.

AFAIK, the Chroma signal only carries the colour info, but with no composite sync...

http://en.wikipedia.org/wiki/S-Video

The other main difference between Composite and S-Video is that the Luma signal is not modulated by the Chroma, so you don't get that evil "running ants" or "dot crawl" effect on bright colours.

I doubt I'll be able to generate the Chroma signal on this tiny CPLD unfortunately, so it'll be easier just to stick a Comp / S-Vid encoder chip on the final board.

OzOnE..

 

That is strange especially since there are more Sega consoles out there that use the Genny Model 2/MD2 connector than Saturn consoles themselves. I'm not sure but I think the 10 pin mini-din male cable connectors are more common than their female counterparts. Maybe the 10 pin mini-din is making a comeback? If so then that is awesome and makes life so much easier!.. maybe.

All this talk about Saturns and their A/V ports makes me want one so badly but they are getting expensive here in the USA. ~$80 for a model 1 Saturn with a single controller and craposite AV cables and a power cord I already have is kinda ridiculous.

Lol. While S-Video is great and all, nothing beats pure 15KHz RGBS via SCART... except everything that came after it like 31KHz RGBHV VGA, DVI-D, HDMI, Display Port, Component (debatable), D-Terminal, etc.

I have to admit, while composite video sucks for normal uses, it was really helpful during my Genesis Model 1 region mod testing phases. I had to hook up the Genny to an old RCA Colortrak CRT to test if my switches were working right. Funny thing about 50Hz on US TVs, they display it but incorrectly. My CRT had the image flickering all over the place and my HDTV, which does NOT accept PAL (sadly), displayed the image in black and white but off center. Somehow Sonic 1 was still playable like that. I hooked it up to my converter via RGB SCART and everything works fine. How did you guys in PAL land survive with a slower Sonic 1? I had to get the speed shoes power up just for it to run at NTSC speeds!

Wait a minute. That last part gave me an idea! Would it be possible to include a way to put the GGs in the PAL format or at least NTSC50? It would be really helpful for Master System games that run too fast in 60Hz.

 

480i and 576i have half lines somewhere in the video iirc. Do you do anything special with those to get your progressive timing. Or does the TV not really care if there are also half lines in a progressive image?

 

The "half line" occurs in every field and the only thing that really makes it a half-line is the fact the VSync starts or ends in the middle of it instead of at the beginning. When the lines are processed just based on the HSyncs, the linedoubler always sees complete lines on the input and always outputs two complete lines for each of them. The only way you could get a half line on the output is if the start of the VSync signal was explicitly moved to the middle of a line, which would make the signal interlaced again (now 960i) - but there is no reason to do so.

 

I see, so if I understand it correctly, 240p and 480i have the same amount of pixels (including blanking) in a frame/field? It is just that the VSYNC timing is different.

Edit: not sure if my description is clear. But as I understand it, in 480i the VSYNC signal comes in the middle of a line and that is the only real difference? All lines are still the same length as in 240p?

Edit2: had a look on the decoded N64 VSYNC and HSYNC signals when displaying 480i. It seems to output 262.5 lines per field. On one of the fields it puts the VSYNC at the half of the 262nd line. So yes, I guess if you line double that you get 525 lines total, which is more accurate to specs than line doubling 240p (has 263 lines per frame). So I guess this also means the VSYNC frequency is slightly higher for 480i signals? I was hoping a 240p frame would take exactly as long as a 480i field but it does not seem to be the case for N64 and I also do not think it is the case for Gamecube, but have not checked it. Just wondering, does your TV lose sync for a while with the HDMI mod when switching to 480i if you have line doubling enabled?

 

I have 100 of these cable connectors, shoot me a pm and we can work something out.

 

Are they female PCB mounts or the cable plugs with housing?

 

They are the males with housing like you would see on a standard Saturn AV wire.

 

Oh ok, the ones we need are the PCB mount female connectors.

 

So about the GG mod... I just had an idea about the Sega Saturn 10 pin mini-DIN A/V port: why not get them 3D printed or ran through a CNC machine? It would instantly solve all of our problems!* These new 3D printed connectors could also be used on other consoles like the Genesis/Mega Drive as a replacement to the 8 pin DIN and 9 pin mini-DIN so we could add S-Video to Genny/MD and even the Master System! I'll start a new thread about getting the connectors 3D printed.




*DISCLAIMER: It will only solve problems related to the connector and parts of the A/V modding community.

 

It might be an idea if you're desperate, but I think I'll stick with the 9-pin sockets.

Trying to get the pins and other bits for the 3d-printed sockets will be a proper pain tbh.

I'm still working on some GG stuff (trying to get the new LCD itself to zoom the image in by compiling new firmware).

I should make another thread though too, as this was meant for the GC.

OzOnE.

 

Wait, if I'm understanding this correctly, Ozone you are making an hdmi board for the game gear correct?

 

The more I think about it, the less I want to use 10 pin mini-DIN. 9 Pin would be best for people like me who don't have Saturn cables but do have Genesis Model 2/MD2 cables. If only 10 pin mini-DIN wasn't a rare connector...

I wonder if we could one day could get cheap replacement LCDs that tap directly into the digital GG signals and display a pure digital signal. That would make playing the GG easier and give it better battery life. Seriously, 4-7 hours on 6 AAs? Sega, there is this nice word called "THINK", you should try it some time. Maybe you could stop making bad Sonic games and start making good ones or better yet, re-release the GG and the Nomad with 32X support and Master System support right out of the box and give them true digital screens!!! My rant is over.

If you want to make a thread for the GG then go ahead and do it! =)

 

Sorry I haven't read the entire thread but hows this project going?
Has anyone built a working PCB?

 

Y'know, I was just about to ask the same question, I've completely lost track of this thread, someone mind giving us a quick cliff-notes review?

 

There are two versions: a Analog version you have to order boards and solder components onto and it gives you Digital audio, 31KHz 480p RGBS (PAL Units natively output RGBS but in 480i/576i at 15KHz only), VGA, and YPbPr Component video, and a true digital DVI/HDMI version that you have to order an FPGA for and solder to the gamecube. The DVI version doesn't require soldering any components to the FPGA other than wires to the gamecube and optional switches for scanlines and line doubling 240p/288p to 480i/576i or any of those to 480p/576p (its like upscaling but it isn't true upscaling). Digital Audio is still in the works for the DVI version.

 

Yep, I agree. It's probably not worth the effort to try to get hold of large-ish quantities of the 10-pin PCB socket tbh.

I'm sure I could make the RGB SCART / Composite / S-Video / Component cables cheaper than they are online too.

I was actually working on that yesterday - I found some source code online for the MST703 scaler chips often used on the small 4.3" replacement LCD controllers.

I got the source to compile fine, but now I need to figure out the correct timings for the LCD itself (I might need to disassemble the stock firmware).

The chip can actually accept digital video directly, as well as most of the usual analog inputs.

What I ideally wanted to do first is just to enable zooming / scaling on the LCD so the GG image would fill the screen.

Eventually it would be great to connect the LCD directly to the GG.

The problem is, the original LCD ribbon cable is pretty wide (and has 68 pins!), so it would be pretty hard for the average modder to solder a new one to the main board. That's even if a modern LCD can be made to work directly with the GG.

It's probably a better idea to just decode the usual video bus on the FPGA or CPLD, then output the data to a new LCD with it's own controller / scaler.

This LCD scaler chip can take RGB input as well, and I reckon that would still look miles better than the stock LCD.

So it's not completely necessary to get a direct connection from the original LCD pins to the new LCD tbh, just a nice bonus if it can be done without too much hassle or expense.

(If I can find a different LCD + controller that has all the input pins available, we could still make a direct digital connection to the GG via the FPGA.)

So yeah, still working on that stuff.

OzOnE

 

I am very excited for that! When can I throw money at the screen? What LCD are you using that accepts RGB? I have been trying to find one so that when I get a nomad, I could get a portable RGB screen but to no avail. I think it would make a great replacement screen for the Nomad as it natively outputs RGB so all you would have to do is solder to R,G,B, and Sync (or Luma if you really want to). When you are done, please let us know as I would love to make my GG better! If you need someone to test your designs, I would be more than happy to help!

 

Yep. I've been working on a generic HDMI output board which could be used on many consoles / computers / scalers.

(The prototype I have atm was made by [RDC] from the gc-forever forum. It's working well on the GC, but he doesn't have time atm to work on getting more boards made. So, I'm finishing my own PCB layout.)

If you also replace the LCD in the Game Gear with a newer modern one, there's then plenty of space behind the LCD to fit the HDMI board too.

The HDMI board could be used simultaneously with the analog output board too (RGB, and probably Composite + S-Video). I'm close to finishing the final design for both boards.

Some consoles / computers are better candidates for the HDMI mod though, as they have fairly easy access to their digital video bus.

They often need the FPGA to do some minor format conversion as well. Those include...

N64
Gamecube
Game Gear
Intellivision

Dreamcast / NAOMI
Atari ST
Wii (any point, since Wii U is out?)
Game Boy
PC Engine / TurboGrafx 16 (exp port dig video?)
Philips CDi


Others will likely not even need the FPGA, and the video data can be fed directly to the HDMI chip. Including...

PSX
PS2
NeoGeo MVS / AES / CD
Atari Jaguar
Xbox 1
Amiga 500 / 1200 / CD32
Panasonic 3DO


Unfortunately, on other machines, there's no direct access to any digital video signals. The only practical way of HDMI modding those is to run a version of their video hardware as a core inside the FPGA.

(I believe this is basically what kevtris is doing with his HDMI NES project, since he already coded an extremely accurate FPGA core for the NES PPU.)

Some of those machines would be tricky to HDMI mod, or more expensive due to needing a larger FPGA to fit the video core in. These include...

Master System < TMS9918. Core available.
Mega Drive < Core available (2-player / interlaced needs fixing).
SNES < Partial PPU Core / untested.
ZX Speccy < ULA Core available.
BBC Micro < Core available.
Amstrad CPC < Core available.
C64 < Core available.
Atari Lynx < No core yet? Need to check.
Sega Saturn < No core yet? Need to check.
Sega SC1000 < TMS9929. Core (probably) available.


The above lists aren't exhaustive by any means, and this doesn't even include all the other arcade boards, nor the more obscure home computers.

So, there are tons of machines which could be modded for better digital video output. Once the new board is done, I intend to mod every machine I own.

OzOnE

 

Well, the LCD I'm trying to mod atm is from one of these cheap reversing monitors...

http://www.amazon.co.uk/gp/product/B0056WJP1M?psc=1&redirect=true&ref_=od_aui_detailpages00

But, the controller board doesn't break out the pins from the chip for the RGB inputs.

So, you would have to solder wires directly to the MStar scaler chip, then patch the firmware to enable the RGB input.
I can do the soldering OK, and I'm working on getting the firmware modded.

The alternative is to find another small controller + LCD on AliExpress or somewhere which does accept RGB out of the box (or with minor mods).
I've seen people mod the Nomad with new screens, so it would be worth checking if they found one with RGB too.

I do have some source code for both the MStar MST series of LCD controller, and the Realtek RTD266x series though.
I'm hoping to compile firmware for most of these common chips which enable all inputs and features we need for modding handhelds (and for other projects ofc.)

Thanks for the offer of testing.
Most of my projects take a long time though, so as always, I can't promise anything yet.

I've just ordered two more of those reversing monitors.
I'm having to de-solder the SPI EEPROM on the controller board every time I want to test new firmware atm, so I need to find a more practical way.

If I manage to enable the better video inputs and adjust the scaling, I'm considering making my own PCB layout for a "Universal-ish" LCD controller.
The MStar scaler chips only cost around $2.50 per piece in small quantities, and they support tons of input types including digital and Component!

I think they only support output to 6-bit LCD panels, but that still covers many choices, and the image quality can be excellent.

Of course, I also want to get scaling working on the GG analog and / or HDMI board, so the image will show full-screen without the big borders.

OzOnE.