Dreamcast and Mame cabinet

[Miller]

Is it possible to wire up a Dreamcast and a Mame PC to a Naomi uni cabinet control panel at the same time, ie without having to keep switching over from one to the other, thanks.

[ark_ader]

I had to have a switch to my DC and PC when I had them connected.

I thought you would fry your CP or DC if you didn't.

[NickG]

There are quite a few possible ways to connect your Mame PC and your DC to a control panel without having to manually switch them.  It all depends how much work and/or money you are willing to throw at the project. 

[moloch]

I am looking to to the same thing with at least one dreamcast.  I am hoping to link 2 up and do head to head cabinets for Virtual On. I am thinking about using some kind of modified KVM switch or something. I just started thinking about this last week. I will keep watching this thread and if I come up with anything I will post it here.

I have also though about using one of those 2 jamma boards in one cabinet things and wiring up the DreamCast to a Jamma finger board and my J-Pac to the other......

[Miller]

Ok ive made my own wiring and connected all the CP wiring to a terminal block, then i wired the Dreamcast and PC to this term block, the Dreamcast is working fine but the PC with an I-Pac is not because im only getting 1.25V as opposed to 5V but when i disconnect the dreamcast wires the PC is ok and i get 5V. So my question is how do i stop the Dreamcast pad drawing all the volts? 

[moloch]

I am gussing here, but why not put a 12v or 5v  line from a PC power supply to the power block and wire one of these to make sure that it does not spike:
http://www.radioshack.com/sm-5v-fixed-voltage-regulator-7805--pi-2062599.html

[Miller]

I think that would break things because your adding more volts to exsisting volts which would exceed the 5V limit, i think.

[moloch]

That is the point of the voltage regulator.

[moloch]

Actually, you make sure that the regulator is the last thing before the block.

That way it will not exceed 5v.

[moloch]

I use a lot of the 5v regulators for Arduino Projects and for LED's. I have pushed them up to about 30v and they work great. I have never gotten anything higher then 5v out.

[Miller]

Ok now im confused lol
The wiring from the dreamcast and PC are both connected together then screwed into the terminal block and on the other side is the original cabinet wiring which goes to the controls. When i go to use the PC the dreamcast is drawing some of the volts hence the reason im only getting 1.25V. I understand how the regulators work but dont get where i would put them and how they would stop the dreamcast drawing volts when im not using it?
I hope that makes sense.

[lettuce]

Have you thought about the using the DC emulator NullDC instead of an actually DC. It runs 80% of games pritty much flawless

[moloch]

Post some photos of the wiring.

In my cabinet I am using a PC power supply to provide extra power for a stereo amp. I would take extra power from that, but without seeing where you are getting power and what the connections are it is a little tough for me to wrap my head around it.

As far as I am concerned about NullDC is that I cannot find complete versions many of the game that I want. They have the music stripped out or things like that. I am interested in this project because as I said I eventually want to run head to head Virtual On games with friends (and not on split screen).

[Miller]

Im not convinced about NullDC alot of messing about when the Dreamcast is so cheap and 100% working, maybe in a few years when its running properly.

Ok heres a pic of P2 controls http://i108.photobucket.com/albums/n30/HornetAoE/SSA52195.jpg as you can see the wiring goes from the term block to the cabinet controls then the wiring for the Dreamcast goes from the block to the pad which is then plugged into the dreamcast through the light grey wire you can just make out that runs inside the cabinet and out the bottom. The other wires going off to the middle of the screen from the block are for the I-Pac and then into the PC.
I was thinking of splitting the original control wires and using two term blocks which i am pretty sure would solve this although splitting the cable is not ideal as it would weaken it and i dont want to keep rewiring it.
Hope this helps any ideas?

[moloch]

The only part I am confused about is that the i-Pac should get its power from the usb so that should be independent.

I am not an electrical expert and from what I see it looks like this....(see attached pdf)

I am not sure where the draw is coming from then.

I am sorry I am not familiar enough with those control panels.

[moloch]

actually after looking at the photo a bit more it may be that you can put a Diode in place on the 5v line that connects through the panel and that would block the dreamcast pad from drawing on it. Again I am still guessing a bit here.

[Miller]

Im no expert either but its definatly the Dreamcast pad thats causing the problems, if you look in the picture at the bottom terminal you can see ive disconnected a green wire out of the block this is from the Dreamcast and the I-Pac is now getting 5V for that button, also i have 3 independent buttons that dont use the term blocks (not shown) instead they go straight to the I-Pac and they also are getting 5V.
I think because the two wires are connected together some of the I-Pac volts (3.75V) are going to the dreamcast pad instead of getting to the controls, just cant see an easy way round it.

[moloch]

A diode would block the current flow to the dreamcast pad or if it is a zeener diode I think that it will limit it.

http://en.wikipedia.org/wiki/Diode

Plus I am going to guess that if you disconnect that green wire it will not work, right?

[Miller]

Disconnecting the green wire stops the Dreamcast button working but lets the I-Pac get the 5V it requries for that button, reconnecting it reduces the I-Pac voltage to 1.25V which is not enough to work however the Dreamcast will be working again.
I did a bit of an introdution to electronics a while ago and remember (i think) that transistors in parallel stop voltages dropping but no idea how to incorperate into this. Although i think you might be right with the diode thing, need to look into it a bit and have a play around with the controls.

[moloch]

Do you know where I can see a schematic of this type of cabinet? That will help me a bit too.

[Miller]

The cabinet is a Naomi universal but the wiring has been made by me so a schematic would be useless really , your PDF file was correct with the Dreamcast and I-Pac PC both supplying an independant 5V source just the Dreamcast pad seems to nick the PC source  . I am going to have a mess around with it tomorrow and see if i can split the original wires from the controls into two and see what that does. I will let you know how i get on and thanks for the help much appreciated.

[NickG]

If your Dreamcast is working fine even with the Ipac connected, but not the other way around, then you could employ a SPST solid state relay per input line, which will break contacts with the Dreamcast collectors when you wish to have your IPAC function.  You can get these with five volt coils which could be wired to your PC. How exciting!  If you wish to get even fancier or cheaper you could use some 4066 or 4016 switches.  In fact, these are of  what some jamma switchers and A/V switchers are comprised  These can also easily be configured into a [make PC - break DC]  / [make DC -break PC] configuration.  I don't quite understand how a voltage regulator would help in this situation; a schematic would really help there.  Old fashioned diode blocking might work though - not sure.     

[moloch]

I only suggested the voltage regulator if you are going to add voltage to the line, that way you insure that you do not exceed 5v.

[NickG]

Oh! it finally snapped; I get it now, thanks.

[ark_ader]

Is there a point to all this messing around, when you can just have a switch box?   

[ShoLouie]

Where would i be able to find a switch box or even a rotary switch for so many buttons?

[northerngames]

it's called a db25 switchbox they carry them at radioshack ebay amazon and hundreds of more places on the net.

you will get 24 signals and a gound on each of the db25 plugs becuase they have 25 seperate pins.

also your dc need seperate ground for 2 player and probably why your voltage is going crazy.

use a db25 switchbox for your arcade controls ipace and dc controls then use a db9 switchbox for your video for pc and dc.

this way everything is seperate and on its own path and is safe this way for sure.

dc ports are very picky and feeding them outside voltage is not recommended.

[moloch]

While I think that the switchbox is a totally valid solution. I am looking for something more elegant. Although I am going to set my cabinet up a little differently then "Miller". I am using a standard Jamma Cabinet that has a j-Pac. I am going to try some kind of Jamma Switching. Or I have one cabinet that is completely custom at this point and uses a standard computer monitor. I may set that up with a dreamcast, but I would probably use some kind of KVM switch......

[moloch]

i am not trying to hijack this thread though. I think Miller has a great idea, I am just spitballing....

[NickG]

Is there a point to all this messing around, when you can just have a switch box?   

Sarcasm aside; the point is to have automation.  You could call the Dreamcast (or your choice from many consoles) up from a frontend, if you really desired.

[moloch]

How do you call up the physical console from a frontend, and switch back? That would be the  !!!!

[Miller]

Apprantly somebody else has does this setup already and got it working without fancy solutions and im waiting on his reply, will let you know what his solution was.

I am already using switch boxes for audio and video but dont want to use it for the controls because it means opening the CP up and it needs to be as simple as possible to operate for the kids when im not about.

I understand what your saying about using NullDC with a frontend and it would be great with no disk swapping and no DC but im not convinced that 80% of the games are now running perfect and what is the minimum spec on the PC?

[ark_ader]

Is there a point to all this messing around, when you can just have a switch box?   

Sarcasm aside; the point is to have automation.  You could call the Dreamcast (or your choice from many consoles) up from a frontend, if you really desired.

No.

This thread is going nowhere, and the switch box solution is a viable and easier solution.  Want an elegant solution?  Install a toggle switch instead of a switch.   

Its baffling why anyone would want to smoke their DC or PC over petty laziness is totally beyond me. 

Lets put our energies into something viable and not vaporware or disaster.

I have done the same thing with the X arcade.  Four consoles and one PC all working together via one controller.  No electronic wonders, no smoke and mirrors, just basic common sense and a fraction of physical activity.

Think that was bad?  I had a MagicVGA switched for each console and PC.  It looked way cool too.  No KVMs.  No wiring headaches.

Want it all from a frontend? 

Find an emulator.   

[Miller]

Is there a point to all this messing around, when you can just have a switch box?   

Sarcasm aside; the point is to have automation.  You could call the Dreamcast (or your choice from many consoles) up from a frontend, if you really desired.

No.

This thread is going nowhere, and the switch box solution is a viable and easier solution.  Want an elegant solution?  Install a toggle switch instead of a switch.   

Its baffling why anyone would want to smoke their DC or PC over petty laziness is totally beyond me. 

Lets put our energies into something viable and not vaporware or disaster.

I have done the same thing with the X arcade.  Four consoles and one PC all working together via one controller.  No electronic wonders, no smoke and mirrors, just basic common sense and a fraction of physical activity.

Think that was bad?  I had a MagicVGA switched for each console and PC.  It looked way cool too.  No KVMs.  No wiring headaches.

Want it all from a frontend? 

Find an emulator.   

Why am i going to fry my PC or DC? and why is this a lazy solution is it not being lazy by buying a switch box without attempting to do it another way?
Like i said i dont want to open the CP and start switching over controls and also bear in mind that this cab is a Naomi uni therefore space is very tight and an external switch box is ugly period.

[moloch]

I do not think that this is a useless exercise. We can all learn something. Or just do not follow the thread if you do not like it....

[northerngames]

to be honost with a trackball spiner buttons joys and wiring your not going to get the switchbox in your cp anyhow.

place it on your coinbox so when you open the coin door it is right there if that is an issue.

you could wire a switch from the toggle switch and mount it anywhere on the cab you wanted really.

there are big bulky models and there are smaller models like the radio shack version.

if you use DB25 and remember your pinout you then can connect any console of choice the same way f you need to swap it out unplug it and put the new one in no tools needed.

any other way plan on spending hours trying to find what wire goes where and to what on each console connected and tools needed and alot of time that could be saved in less time by making it DB-25 istead once its done its done after that everything else can just plug in.

[NickG]

How do you call up the physical console from a frontend, and switch back? That would be the  !!!!

Use an Ledwiz (or similar) or a serial controller to drive your switchbox(es) and power relays as well.  Keep an escape/quit button un-switched.
One plan I have thought of is to use Mala's serial plug-in, in combination with an IR blaster circuit and an IR A/V switchbox, and some IR KVM's.
Another - probably easier and more reliable- is to tap the switch lines directly to +5V from LedWiz (or similar) outputs.
I mentioned these ideas before in the project thread in my sig.

[moloch]

Nice. That is awesome.....

I will look through your thread. I glanced through it. I will now go through it with a fine tooth comb.

[ark_ader]

Why am i going to fry my PC or DC? and why is this a lazy solution is it not being lazy by buying a switch box without attempting to do it another way?
Like i said i dont want to open the CP and start switching over controls and also bear in mind that this cab is a Naomi uni therefore space is very tight and an external switch box is ugly period.

You mount the switchbox from inside, use a dremel and make a small hole where the shaft of the switchbox will be made available and either extend the shaft of the switchbox, or get a cover that will marry the colour of your cab.  Put some decals next to it, and it will look the business.

Nobody would know.  Or you can just get an electronic switchbox and wire it to a momentary switch.  Some of those switches are very small.

I agree that manual switchboxes are unsightly, but there are ways to conceal them.

[Miller]

Why am i going to fry my PC or DC? and why is this a lazy solution is it not being lazy by buying a switch box without attempting to do it another way?
Like i said i dont want to open the CP and start switching over controls and also bear in mind that this cab is a Naomi uni therefore space is very tight and an external switch box is ugly period.

You mount the switchbox from inside, use a dremel and make a small hole where the shaft of the switchbox will be made available and either extend the shaft of the switchbox, or get a cover that will marry the colour of your cab.  Put some decals next to it, and it will look the business.

Nobody would know.  Or you can just get an electronic switchbox and wire it to a momentary switch.  Some of those switches are very small.

I agree that manual switchboxes are unsightly, but there are ways to conceal them.

Ok ive been looking into this a bit more and it seems using a Y cable for DC and PC controls which is in affect what im doing causes grounding issues and like you have already previously posted it is more hassle than its worth. I spoke to another guy who said he had a solution using terminal block connectors but it turned out all he was doing was using male and female plugin term blocks and swapping them over when he wanted to change controls, which is not what im looking for.
So a switch box as you have righly pointed out looks like the only real viable solution in my case 

Are these the type of switch box you are talking about? http://www.amazon.com/tag/lpt%202%20port%20switch%20box%20printer%20db25%20mechanical%20manual and wire each cable to each pin?

The box above looks way too bulky so ive been looking around and do you think this one would be ok http://www.amazon.co.uk/Belkin-Compact-Parallel-Switch-Printer/dp/B00004Z6QT/ref=pd_sbs_ce_title_1 it looks ideal for my purposes as it is automated (no switching) and compact (will fit in CP) and also capable of adding more console controls in the future.
Let me know what you think thanks.