Wiring an MGCD (JAMMA Dreamcast)...

NERDtendo

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I bought an MGCD (Dreamcast to JAMMA console) without any info about it. My Google-Fu got me bits and pieces of good tips and misinformation. I decided to make a thread with the correct way to hook up one of these units (through the scientific method of trial and error). Any help along the way is much appreciated. Once I have a fully working system and have the system all figured out I will make these first couple posts the be-all-end-all source for the MGCD Dreamcast system.

Here is the MGCD pinout....



I am currently testing it in my Dynamo HS-5 with Mortal Kombat 2 installed. Here is it's pinout...

|-----------------|---|----|---------------|
| Solder Side | | | Parts Side |
|-----------------|---|----|----------------|
| Ground | A | 1 | Ground |
| Ground | B | 2 | Ground |
| +5VDC | C | 3 | +5VDC |
| +5VDC | D | 4 | +5VDC |
| -5VDC | E | 5 | -5VDC |
| +12VDC | F | 6 | +12VDC |
| (Key) | H | 7 | (Key) |
| N/C | J | 8 | Coin Counter |
| N/C | K | 9 | N/C |
| Speaker (-) | L | 10 | Speaker (+) |
| N/C | M | 11 | N/C |
| Video Green | N | 12 | Video Red |
| Video Sync | P | 13 | Video Blue |
| Service | R | 14 | Video Ground |
| Tilt | S | 15 | Test |
| Coin 2 | T | 16 | Coin 1 |
| Start 2 | U | 17 | Start 1 |
| Up 2 | V | 18 | Up 1 |
| Down 2 | W | 19 | Down 1 |
| Left 2 | X | 20 | Left 1 |
| Right 2 | Y | 21 | Right 1 |
| High Punch 2 | Z | 22 | High Punch 1 |
| Block 2 | a | 23 | Block 1 |
| High Kick 2 | b | 24 | High Kick 1 |
| N/C | c | 25 | N/C |
| N/C | d | 26 | N/C |
| Ground | e | 27 | Ground |
| Ground | f | 28 | Ground |
|------------------ |--|---|-----------------|

Which coincides with the standard JAMMA pinout here...



Next, onto wiring the controls...
 

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MGCD is not JAMMA plug-n-play...

First things first...the MGCD is not JAMMA plug-n-play ready. It does require alterations to the JAMMA harness. I didn't want to hack or change my JAMMA harness in my Dynamo HS-5 so I bought a JAMMA extension harness to make my alterations to and to hopefully make a plug-n-play JAMMA adapter for my MGCD so it can go into and JAMMA cab that is wired for +5v, +12v, AND -5v. The MGCD requires that the -5v be hooked up. This rules out my ST-V Die Hard cab unless I add -5v to the JAMMA loom (a little sad because I had hope to use that cab for this).

If you take a look at the harness pinout from the previous post, you will see that the MGCD wires all of the buttons to the edge connector instead of going the standard "Kick" Harness route. This poses a problem for standard JAMMA cabs because the last two connections on a regular JAMMA edge connector are set for grounds and the MGCD want them to be used for buttons 6 & 7 for 1P & 2P. (***If you want to have access to 6 buttons for fighting games, you need to send the two grounds that are currently there back over to the power side grounds on the JAMMA extention harness and then connect wires that will go from the extension harness directly up to the control panel...or make a Kick Harness.***) I am personally not concerned with the fighting games as I got the MGCD for the SHMUPS so my tutorial here will be using the standard three buttons that are usually populated on a standard JAMMA harness. In the case of my MKII control panel, High Punch (A), Block (B), and High Kick (C).

In order to get the controls on the arcade cab to work you need to cut the last two connectors (27 & 28 on both sides in the JAMMA Pinout Diagram above) and splice them into the power ground (1 & 2 in the JAMMA Diagram above). If you don't connect them to ground, none of your controls will work. This is different from what has been posted elsewhere that said you can just cut and cap off the wires or just lift the pins.

I will post some pictures (here) of my JAMMA Extention Harness that will be my dedicated MGCD JAMMA Adapter. This first round is learning from ground zero. When I get this finished, I plan to make a cleaner, more professional JAMMA Adapter.


Next step is learning how the run the damn thing...
 
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Owner's Manual...

The only Operation Manual I could find for the MGCD is for the Model B which does not include a case, the dip switches, are relocated onto the PCB instead of through a daughtercard connected by a ribbon cable, and it looks like the addition of a port for a VMU. I could not manage to zip the manual small enough for KLOV to allow me to attach it to the post, but it can be downloaded here for the time being...

http://www.starcab.net/ressources/docs/conv/MGCD-B.pdf

I attached a different User Guide that I found (again, for Model B). It goes into more detail about the system, but excludes all of the dip switch settings for the compatible games. (Also, it has a different Pinout...which I will get to later when I talk about the technical difficulties I am currently having)

So when you have it wired up and you are ready to use your Dreamcast in your JAMMA cab like a cool dude, you run into a small snag. If you are rocking a NTSC-U (American) console, there are only about 18 games that are compatible with the purpose of the MGCD. The MGCD is set up so that it can hide all of the telltale splash screens that would give it away that you are using a Dreamcast instead of the NAOMI system. If you insist on using your US console with the MGCD you will have to resort to the good old time per credit play function. With that arcade lame, but home console cool function, you can play most any game you want (as long as it is US region of course). You will have to put up with a timer popping up on the bottom of the screen every minute to tell you how much time you have left. The maximum time per credit is 256 minutes for 1 coin. I'll get into the dip switch settings next, but first, the game that are compatible with the MGCD...

The MGCD is made for the Japanese Region Dreamcast (NTSC-J) as there are more than 100 titles compatible with it vs the 18 US games. On top of that, all of the excellent SHMUPS are only compatible with the NTSC-J version and console. I do not currently have an NTSC-J console, but it should be in the mail headed my way soon.

Next topic....the dip switch settings (somewhat confusing)...
 

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Dip switch settings...

The dip switches are a little confusing, but here is goes...

There are two banks of dips. One set has 8 switches and the other has 12.

The 8 switch bank refers to the console and the game title. If you have a compatible game, look in the back of the Manual and located the game title. It will give you the code you need to set for the 8 switch bank. For example, Gunbird 2 (NTSC-J region) has a code of "23678 on" so to set the MGCD for that title you turn on the switches numbered 2, 3, 6, 7, and 8 while leaving switches 1, 4, and 5 off. That will tell the firmware which game you are going to be playing arcade style and it has the proper screenshots in it's memory to know where the title screen is and not display the splash screens and also removes the other options of the game and just runs the available "Arcade Mode."

If you have games you want to play that are not supported in the dip switch settings you must set up the MGCD to recognize the type of console being played. The MGCD can be used with the Dreamcast, PSone, and PS2 according to the manual. It looks as though all you need is the proper controller ports to switch from a DreamCast MGCD to a PS2/PSone MGCD, but I cannot confirm this. I say this because of the following...if you set all of the 8 switch bank dips to on it will be set for Dreamcast, if you set all of the 8 switch bank dips to off it will be set for PS2. I have not yet found if there is a setting for PSone. All splash screens are present for games that are not supported by the dip settings.

If you set the wrong switch code on the MGCD it will have a random number on the bottom of the screen that won't disappear and the game won't boot properly.

The 12 switch bank is all about the credits and difficulty. Switches 1 and 2 determine how many credits to give per coin inserted. Switch 4 on and Switch 3 off sets the MGCD to credit play and turns switches 5-7 to difficulty settings, 8 and 9 for speed/time settings, and 10-12 to number of rounds/lives/continues allowed.

If you set switch 3 on and 4 off that puts the MGCD into time play mode. In Timer Mode, switches 5 through 12 all determine the amount of time that is awarded per coin inserted. For console/at-home users the generally accepted settings is 5-12 on which gives 256 minutes per coin inserted.
 
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Burned games on the MGCD...

I do not have any original copies of games at the moment. All I have been testing with are burned copies. Of the 5 I tested, only 1 didn't work. Obviously, you would need a Dreamcast capable of playing burned games in order for this to be an option. Also, this only applies to US consoles for sure right now because that is all I have. Even games that have a splash screen prior to the normal game's operation (i.e. echelon) work.


NEXT...my current technical difficulties...
 
Sound problem...no sound at all!

I have no sound currently and I am not sure where to begin to fix it. Here's where I could start using some input from the world of KLOV technical department...

The manual that includes all the dip switch settings and the list of compatible games (the one where you have to click the link to obtain...not the Word Document that is zipped as an attachment), which I will call MAN1, says that it is very important that you have the -5v connected...



It is reflected in the pinout, which I will call MANPIN1, that it provides as well...



The Word Document manual, which I will call MAN2, has no such warning about the -5v as seen here...



And it is reflected in the pinout, which I will call MANPIN2, it provides as well...





Another part to consider (or not, I don't know so I will put it out there), is that the JAMMA pinout shows the -5v being hooked up to both the Component Side as well as the Solder Side as seen below...



MAN1 and MANPIN1 show the -5v only hooked up to the Part Side of the harness. So I put it out there for thoughts on this matter...-5v on just one side would mean that I need to cut the pin on the Component Side of my MGCD harness if I go with MAN1's instructions? Leave both -5v connected on the MGCD harness because I should be looking somewhere else? Or go with no -5v and see what happens? To try the no -5v I would just plug my MGCD harness into my Die Hard cab which doesn't have the -5v hooked up.


Actually, I just got my plan of attack (try the MGCD in the Die Hard cab) I just needed to type it out to see what I wanted to do. I'll leave up my ramblings and report back what happens in a bit.
 
I don't see the ground for sound. Is this a stereo board? It appears to have four different sound out connections and no returns. This may be why you have no sound.
 
Just tried it in my Die Hard cab and the screen is all scrambled so -5v is required.


I don't see the ground for sound. Is this a stereo board? It appears to have four different sound out connections and no returns. This may be why you have no sound.

I saw the 4 sound connections. Somewhere on the internets I saw the words "pre-amp" next to the L and R inputs. I will see if I can track that one down...there may be yet a 3rd different pinout for this system.
 
Is this cab wired for sound from the Jamma harness or is sound coming from the MK2 sound board? Do other Jamma games work with sound in this cab?
 
Is this cab wired for sound from the Jamma harness or is sound coming from the MK2 sound board? Do other Jamma games work with sound in this cab?

The voice of reason. I will stick anther board in and see if I get sound. Thanks! I have lots of things all going on at the same time and sometimes I overlook the easy stuff.
 
Plugged in a 60-in-1 real quick and sound is present so the JAMMA harness does deliver the sound, not the MKII sound board.
 
OK.

Are there any schematics for the Dreamcast anywhere? What about schematics for the adaptor you are using? I am not familiar with this product.

Also, does it have provisions to plug speakers into it directly or do you have to use a connection to the TV? In other words, I am trying to determine if it has an onboard sound amplification circuit. If it doesn't have an onboard sound amp circuit then you'll need to add one to make sound audible.
 
The only information available on the Internets is the two pinouts I posted. The adapter I am using is the JAMMA extension harness from Twisted Quarter on eBay right now. I am making my adjustments to that harness because the MGCD is not JAMMA plug-and-play. Once the extension harness gets hammered out correctly, I will do a better adapter. I will get those pix up soon.
 
Are all of the voltage lines present in your harness? Are the power lines in your harness 18 gauge or are they smaller? Have you tried the volume control on the MGCD?
 
Are all of the voltage lines present in your harness? Are the power lines in your harness 18 gauge or are they smaller? Have you tried the volume control on the MGCD?

All voltages are present in the harness. The power wires in the HS-5 are the same gauge as the rest of the harness. The voltage wires on my adapter are bigger than the rest of the wires on the harness. Yes, I tried the volume knob...still nothing.

Everything works except the sound and the fan inside the case. Games load up, credit fine, and play with either a Dreamcast controller or through the HS-5 control panel joystick and buttons.





Picture of MGCD Dreamcast running on my HS-5...no sound at all...

 
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