Built a Sega Genesis (Model 2) RGB Cable.....

[RARusk]

On a recent trip to Radio Shack I went over to their game section. I caught a glimpse of a PlayStation 2 controller extension cable. It was one of those breakaway cables which mimic what the Xbox controller does. Anyway it so happened that the two pieces within the clear packaging were disconnected and I could see the plug they were using.

It turned out that they were using the same 9-pin mini DIN plugs that Sega used on their Genesis (Model 2) units. Intrigued, I bought one of these cables (which is the Breakaway Extension Cable (for PlayStation 2) [Part Number: 26-671]) and took it home. This cable is six feet long with the breakaway section adding an additional nine inches.

In the picture below you can see the male plug end (near the bottom), the PlayStation plug end (near the middle - with the cover removed so you can see all nine wires plus ground), and at the top is the female end belonging to the breakaway section.

[RARusk]

In this picture you can see the the completed cable. The PlayStation plug has been replaced with the standard 9-pin plug so I can attach it to my RGB box. In the new plug each of the three video lines are being run through 75 ohm resistors to tone down the strong RGB signals.

[RARusk]

Finally, this is the new cable in action using the game "General Chaos". This cable is not as snazzy as the Belkin cables I nornally use for my RGB cables but it does the job well. In addition, this cable can also be used to construct a Composite Video cable if you need to do so. The cable also costs about five dollars. I don't know how hard it would be for those outside the U.S. to get this particular part for Genesis usage.

Also, you may notice, to the right, part of my new computer setup. It is a new 1.5Ghz Single Core Intel Mac Mini. It fucking rocks. These pictures were processed on it using Graphic Converter after they were taken by my Kodak DC265 digital camera.

[kendrick]

Good lookin' out, if you'll excuse the urban slang. I just cleaned my local Radio Shack out of all these cables. The new project is a video switch that only uses Mini-DIN9 connectors. :)

I think it's worth mentioning though... I picked up six cables, and only five have the DIN socket and plug that match the one used on the Genesis/Megadrive. The sixth one has some sort of weird symmetrical connector that looks a lot like the A/V connector on a Turbo Express (but not quite the same size, sadly.) If yours look anything like mine, they should come in a plastic snap package that's easily opened to check the connector type. So just a heads up to anybody else who's inspired to pick one up.

-KKC, bored at work. I should bring my game modding gear here and claim that it's business-related labor. :)

[Specineff]

Got mine today. Thanks for the tip on the 75-ohm resistors. No wonder why my Genny 2 looked like ass before.

[Aryu Limitless]

Looks like the same connections as the Sega CDX and the 32X.  (Both of which I own.)  I am looking to use my monitor for those, as well.  I'll need a little more info about it, but it shouldn't be too hard.

Where can I find the pinouts for these?  If the pinouts are identical to the Model 2 Genesis then I'll be working on converting these ASAP!  

[kendrick]

Pinout right there on the GamesX front page:

http://www.gamesx.com/avpinouts/genesisav.htm

-KKC, looking to head off Lawrence's predictable aneurysm. :)

[Guest_Aryu Limitless]

(Forgot to Log In, Sorry...)
I got one the other day.  Awesome cable-- I did check it first!

My problem:
How do I connect the HSync and VSync to the 9-pin sub-D monitor end when the Genesis 2/CDX only outputs Sync.

I've connected two different ends of the cables, PS2 Extension and a male 9-Pin sub-D to a perfboard I got from Radio Shack for a cable for my C64 joystick DTV adapter.

Here's what it looks like:
9-pin side

R G B H s V r g b x

1 2 3 4 5 6 7 8 9 x

PS2 extension cable side

The pins for the PS2 cable I've numbered according to the colors and the pinout
I did.
Connections:
1-B    (1=White/PS2)
3-G    (3=Blue/PS2)
5-H ? (5=Yellow/PS2)
7-R    (7=Red/PS2)
r-g-b-x-x  (r=RGnd, g=GGnd, b=BGnd/VGA)  (x=shield ground/BOTH)

s=HSync Gnd
V=VSync

Do I need an LM1881 to separate the H & VSync signals, or can I get away with using the Comp. Video out (4=Green/PS2) to connect it to the VSync or the HSync and connecting the Sync (5=Yellow/PS2) to the HSync?  HSync seems to be the obvious choice; I do get a better signal from it with the Sync line.

(Sorry, no pics.)

[Aryu Limitless]

Also, what's the oblong-shaped box you've got it plugged into?
I'm looking for something like that.

[RARusk]

First off, what monitor are you trying to use? The Genesis only outputs Composite Sync. If you need Seperate Sync you should use either the EL4583 or the EL1883 sync chips.

Second, the oblong box which is my RGB box, used to be a Naki Dreamcast VGA box. It has been hacked repeatedly with multiple revisions, and multiple layers of paint, over the past few years. It houses a Radio Shack portoboard that contains the very nice EL1883 chip. The monitor it is hooked to is an NEC MultiSync 3D, one of the better RGB monitors out there (because it can do interlaced and progressive scan modes).

[Guest_Aryu Limitless]

I'm using a Samsung SyncMaster3 for the RGB monitor.  It's a 9-pin VGA-style pinout, but I can't seem to get it to sync properly.  If I need to build a sync-strainer circuit, can you diagram one for me?

Also, on a related note.  I have a Naki VGA Box for my Dreamcast that I'd like to convert into a "NikfyBox" like yours.  (Shown in the pic with your Mac Mini just off the right edge.)  Maybe you could drop me a jpg of the circuitry you've added and a diagram of this, too.  It'd help me either way!

[Guest_Jay]

Nice work...this looks great.

I'm looking to hook my Model 2 up to a Betson CGA arcade monitor, and I'm definitely going to head to Radio Shack and grab some of those ext. cables.

But...the arcade monitor needs seperate H/V sync.  What's the best way to go about using the LM1881 circuit to pull the sync info from the composite signal?  Is this a mod I should do externally or solder it up on the Genny mobo?

Thanks...

[Guest]

Seems as if the local Radio Shacks have recently changed their stock and I haven't been able to find a single one locally.  Anyone have one they wouldn't mind parting with for cheap?  Thanks...

[jay_mf]

Okay...so I finally registered.

Couple of questions that I was hoping someone could help me out with.

First off, thanks for the heads-up on the PS2 cables.  I managed to find one last Radio Shack that did have them in stock (the store was actually closing for good and just hadn't rotated them out of stock yet).

Aryu Limitless, thanks for the pinout colors on the PS2 cable.  They were correct except for one: the black wire (not white as you have listed) on the cable side corresponds to blue on the monitor input side.

It turns out the CGA (15 kHz) arcade monitor can use the composite sync the Genesis outputs (no need for an LM1881 circuit).  So, after a few tries, I got a really nice picture up and running.  However, the color is a little 'washed' (see picture).  Is this because the RGB signals from the Genesis are strong?  Are 75-ohm resistors necessary to correct this?

[jay_mf]

Here's a closer shot of the screen... Any ideas?

[Aryu Limitless]

Jay_MF, you need to add the 75 ohm resistors on the RGB inputs to help reduce the powerful inputs coming from the Genny.  This should alleviate the washed-out look of the grfx on the monitor.

Also, drop me a diagram of the circuit you used for your monitor to my e-mail address (aryu.limitless@yahoo.com).  Maybe I can alter this a bit to use on my Samsung SyncMaster3.

[jay_mf]

Update...

Here's the color matchup for my particular cable.  Not sure if each one is the same, but it might help someone out there:

Monitor       Cable
Red   --->   BLUE
Green --->  RED
Blue ----> BLACK
Sync ----> YELLOW

Fortunately, my arcade monitor accepts a 1v to 5v RGB signal, so it was able to work well with the strong signal the Genesis uses (no resistors necessary).  Picture looks fantastic...