Dreamcast to arcade monitor.

[jlampc]

  I finally got the Dreamcast hooked up to My arcade monitor. And it looks pretty good. I modified a VGA box using the gamesx hack and It worked almost perfectly.
The one thing I am having an issue with is the brightness. The image's is really bright..almost a little washed out. On a vga monitor it looks fine. The blacks on the arcade monitor are a dark grey. I'm assuming the dreamcast is putting out a hot signal. Anyone know of a way to fix this. I think a resistor or two somewhere might fix it.  Help a brother out  

[Dave_K.]

You will have to calibrate the arcade monitor's brightness levels.  All video sources will have different levels (be it a jamma board or other external RGB source).  You should be happy its bright as most RGB mods (using a scart cable) come out to dark.

[euclidean]

Are you able to post the link to the  gamesx hack.  I want to make sure im looking at the right one.

Thanks.

[jlampc]

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

This showed me the pinout for the dreamcast. I used a Nyko VGA box. It was easy to hack beause the wires are in order when they attach to the VGA board. I snipped #6 and it stopped working on my VGA monitor and started working on my Arcade monitor. I tried out soul calibur and it looks great. (a little washed out -but I'm working on that)..

[Dave_K.]

I don't think gamesx has explicit instructions for hacking the VGA box, but rather how to make your own (with details on the AV pins).   Although I guess after reading that you can pretty much come to the same conclusion.

But its also documented on BYOAC in the Game Consoles section:

http://www.arcadecontrols.com/arcade_consoles.shtml#dc2arcade

[jlampc]

OHHH>>>forgot to mention somthing..the instructions people have posted are wrong. Here is the Website that helped me more.  

http://www.hellspark.com/dm/mame/software/dreamcast/dreamcast-to-arcade-monitor/howto.txt

No pictures...but it matches up with the Pics on Gamesx. you should not cut the #7 wire...I Its the # 6...I double checked it today....The 7th wire is for 15khz  and the 6 th wire is 31khz. cut the sixth and the 15khz kicks in.


Check my links and and confirm my statement...

hope this helps

[Shieldwolf]

I'm confused.
why do you guys do all this rewiring for the dc to play on a monitor?

Why not just use a dcbox?

[jlampc]

I'm confused.
why do you guys do all this rewiring for the dc to play on a monitor?

Why not just use a dcbox?

The Arcade Monitor I'm attaching to is not VGA. Its a standard resolution Arcade monitor running at 15Khz. This requires the Dreamcast's output to match 15Khz. The Regular vga boxes all output at 31Khz without modification. With the mod, the frequency drops to 15Khz. If you are trying to use a computer or arcade vga monitor, then you don't need to modify it.  There was once an add-on for the dreamcast that allowed it to connect to a Jamma harness with 15khz output  It's real hard to find, even on e-bay. I'm not sure if the DCbox your refering to is this or a regular VGA box. Hope this clears up the confusion.  

[Dave_K.]

OHHH>>>forgot to mention somthing..the instructions people have posted are wrong. Here is the Website that helped me more.  

http://www.hellspark.com/dm/mame/software/dreamcast/dreamcast-to-arcade-monitor/howto.txt

No pictures...but it matches up with the Pics on Gamesx. you should not cut the #7 wire...I Its the # 6...I double checked it today....The 7th wire is for 15khz  and the 6 th wire is 31khz. cut the sixth and the 15khz kicks in.


Check my links and and confirm my statement...

hope this helps

These instructions are a copy from what I wrote in the FAQ here on arcade controls (notice they left out the links).  And you are correct, iits pin 6 you cut.

[jlampc]

Thanx Dave,
Your right ...I should have noticed the text was the same as your FAQ.. It was real helpful...

Some of the posts to this group were telling people to cut the wrong wire. I found postings to cut 7 everywhere.  I appreciate your Knowledge and Info

[unicron]

I finally got the Dreamcast hooked up to My arcade monitor. And it looks pretty good. I modified a VGA box using the gamesx hack and It worked almost perfectly.
The one thing I am having an issue with is the brightness. The image's is really bright..almost a little washed out. On a vga monitor it looks fine. The blacks on the arcade monitor are a dark grey. I'm assuming the dreamcast is putting out a hot signal. Anyone know of a way to fix this. I think a resistor or two somewhere might fix it.  Help a brother out  

Yep, you need resistors, bleed off some of the vga boxes R G and B to ground then close that sucker back up and you'll be fine. First time I did it I got no picture, it would display for a second then go to black, so I put 2 parallel 100k Ohm resistors on R, G, and B respectively (per instructions on a VERY helpful post on the ultimarc board with pictures, that hasn't been there for a long time now). Picture perfect ever since.

p.s. I just plugged the modded vga box into a jpac, you may or may not need to resist a different level than I did if you are wiring it straight up, the amount of resistance I used is supposed to be perfect for vga box to jpac to jamma.

[tenex2mg]

Ok Guys, I'm at my wit's end.  I've sacrificed numerous vgaboxes, ordered a new "upfront" control board, but still can't get my dreamcast to display properly on my arcade monitor.  Basically its shifted over halfway and continues over to the other side, the correct wire is cut...i don't know what to try now...it did work for a time (2-3 days) then never again.  

The pc outputs perfectly with an arcadeVGA card, would it be possible to use a TV-Tuner card with a Video-In and hook up the dreamcast that way using either s-video or RCA?

thanks again

jeff

[Dave_K.]

Ok Guys, I'm at my wit's end.  I've sacrificed numerous vgaboxes, ordered a new "upfront" control board, but still can't get my dreamcast to display properly on my arcade monitor.  Basically its shifted over halfway and continues over to the other side, the correct wire is cut...i don't know what to try now...it did work for a time (2-3 days) then never again.  

Are you using both Hor and Vert sync lines to your monitor (from the VGA Box)?  Are you connecting grounds together from any other source (other than the VGA box)?  Or are multiple inputs hooked up to this monitor at the same time?  Is this direct to the monitor or through a Jamma finger board?

[tenex2mg]

I'm using the vga cable that came with the ArcadeVGA card , one end is connected to vgabox, the other is spliced and connected to R G B ground (on first set of pins on monitor)  Hsync Vsync Ground (second set of pins on the monitor), there's no Jamma finger board....any thoughts?

-jeff-

[b3atmania]

The Arcade Monitor I'm attaching to is not VGA. Its a standard resolution Arcade monitor running at 15Khz. This requires the Dreamcast's output to match 15Khz. The Regular vga boxes all output at 31Khz without modification. With the mod, the frequency drops to 15Khz. If you are trying to use a computer or arcade vga monitor, then you don't need to modify it.  There was once an add-on for the dreamcast that allowed it to connect to a Jamma harness with 15khz output  It's real hard to find, even on e-bay. I'm not sure if the DCbox your refering to is this or a regular VGA box. Hope this clears up the confusion.  

Does this hack work for all games? Especially those that do not support the VGA box in the first place?

I ask since I have a SCART (RGB) cable and some DC games (Gauntlet Legends and Pop'n Music come to mind) do not support RGB output to TV, so I was wondering if this hack would circumvent this RGB lockout?

[Dave_K.]

I'm using the vga cable that came with the ArcadeVGA card , one end is connected to vgabox, the other is spliced and connected to R G B ground (on first set of pins on monitor)  Hsync Vsync Ground (second set of pins on the monitor), there's no Jamma finger board....any thoughts?

-jeff-

When you say the picture is shifted over half way, do you mean vertically or horizontally?  Either way, this is an indication that something is wrong with your Hor and Vert lines, either a bad connection in the cable, or inside the VGA box.  Have you tried hooking up the VGA box to a computer monitor to confirm its still outputing 15khz?  Since you say it worked for a couple days then stopped, do you think there is a possibilitiy that the wire you cut has moved and is touching something that is grounding it out?

[Dave_K.]

Does this hack work for all games? Especially those that do not support the VGA box in the first place?

I ask since I have a SCART (RGB) cable and some DC games (Gauntlet Legends and Pop'n Music come to mind) do not support RGB output to TV, so I was wondering if this hack would circumvent this RGB lockout?

No, games like Gaunlet Ledgends will still have problems with the hacked VGA box.  BUT, there is a work around!  Most of these games  can be fooled by first booting up in "tv mode" and then switching it over to VGA mode after a couple seconds (approximately when the sega logo should be displaying).  I'm sure you've herd of this "switch method" to also get non-vga games to display in full VGA.

Unfortunally you can't do this switch method with a SCART cable.

[tenex2mg]

I've tried hooking up to regualr computer monitor, and got the out of range error...indicating that its outputting to 15khz, though the wire could be a problem, i'll sacrifice my old  monitor to see if that makes a difference.  Woud there be a different pinout between the vgabox and say my arcadevga card?  Because as I said before the PC outputs to arcade monitor just fine...

as always thanks

iniatially i used a vgaswitch box to go from DC to PC but this was when I was using a computer monitor in the cab...

[Dave_K.]

The thing that confuses me is when you said it had originally worked fine for the first few days.  Were you using that arcadeVGA cable then too?  Were you using the switchbox then?  If the dc vga box had its ground mixed with another sources ground that could damage the vga box.  Also since you said you have gone through multiple dc vga boxes, it sounds like you are doing something to fry them.  Sorry but it sounds like your current one is fried too.

[jlampc]

You said that you cut the right wire.. Which one did you cut exactly. I found out that if you cut either the 6 or 7 wire separately it will not display on a VGA monitor(at least with my Naki VGAbox). Only the 6 wire should be cut. I also had to fudge around with the vertical sync and horizontal sync wires before both my VGA and Dreamcast would display properly. I ended up attaching the Vertical and horizontal sync wires,from the dreamcast/PC, to just the Vertical sync ( left the horizontal sync loose)on the monitor then everything was fine. Good luck.  

[consoledirect]

Hi,

I saw you are using the Nyko box to out put video to your arcade cabinet. I am using the exact same one. I am running it on a Sega Megalo 41" monitor which takes 15/24/31 k signal inputs. The only problem is i have been trying to output audio and im not sure if its carried via the 15din 31k video plug or if im supposed to output it from the Nyko VGA box.

Any input would be greatly appricated.

[ani]

Ok Guys, I'm at my wit's end.  I've sacrificed numerous vgaboxes, ordered a new "upfront" control board, but still can't get my dreamcast to display properly on my arcade monitor.  Basically its shifted over halfway and continues over to the other side, the correct wire is cut...i don't know what to try now...it did work for a time (2-3 days) then never again.  

The pc outputs perfectly with an arcadeVGA card, would it be possible to use a TV-Tuner card with a Video-In and hook up the dreamcast that way using either s-video or RCA?

thanks again

jeff

I had this exact same problem with my naki vga box. Ends up the problem was the ground. For me, if I connected the ground to the sync ground, I got your problem, but if I connected it to the ground of one of the colors (the middle row of the 15 pin pinout) it worked fine. I actually just connected all the grounds together, but it didn't appear to change my results. Let me know if you continue to have problems, we can meet in the chat room and compare notes and get ya working, I'm sure it's a solvable problem.

[abrannan]

Hi,

I saw you are using the Nyko box to out put video to your arcade cabinet. I am using the exact same one. I am running it on a Sega Megalo 41" monitor which takes 15/24/31 k signal inputs. The only problem is i have been trying to output audio and im not sure if its carried via the 15din 31k video plug or if im supposed to output it from the Nyko VGA box.

Any input would be greatly appricated.

I'd output it from the VGA box.

[bill55]

I finally got the Dreamcast hooked up to My arcade monitor. And it looks pretty good. I modified a VGA box using the gamesx hack and It worked almost perfectly.
The one thing I am having an issue with is the brightness. The image's is really bright..almost a little washed out. On a vga monitor it looks fine. The blacks on the arcade monitor are a dark grey. I'm assuming the dreamcast is putting out a hot signal. Anyone know of a way to fix this. I think a resistor or two somewhere might fix it.  Help a brother out  

\


I too have gotten the picture to work, but it is way too bright...colors allwashed out and such. I am using the Madness Gameware VGA adaptor. I ran the R, G,B, ground, and sync to my jamma fingerboard. I used 220uF caps on each of my R, G, and B wires. The arrow on the cap is pointing towards the fingerboard.

Any ideas? Why is it so bright? Are the caps on wrong?

Thanks!
Bill

[Dave_K.]

I too have gotten the picture to work, but it is way too bright...colors allwashed out and such. I am using the Madness Gameware VGA adaptor. I ran the R, G,B, ground, and sync to my jamma fingerboard. I used 220uF caps on each of my R, G, and B wires. The arrow on the cap is pointing towards the fingerboard.

Any ideas? Why is it so bright? Are the caps on wrong?

Thanks!
Bill

I have the same dc vga box in my cab, works great.  Your problem is that there are already caps inline with the rgb already (inside the VGA box), no need to put more outside of it.  

[bill55]

Dave_K:

When I take the caps off I get a black screen. Any suggestions? Could you take a pic of yours or something so I can see it.  I have gotten 20 different explanations from 20 different people.

The last person said to take the r,g,b and comp sync right from the connector on the vga board right where it comes out of the DC. I tried that but am having no luck with that either.

PLEASE HELP!!!! Been working on this for 3 days and about 10+ hours on teh video alone!

Bill

[Dave_K.]

Dave_K:

When I take the caps off I get a black screen. Any suggestions? Could you take a pic of yours or something so I can see it.  I have gotten 20 different explanations from 20 different people.

The last person said to take the r,g,b and comp sync right from the connector on the vga board right where it comes out of the DC. I tried that but am having no luck with that either.

PLEASE HELP!!!! Been working on this for 3 days and about 10+ hours on teh video alone!

Bill

Bill, I didn't do anything special but cut wire #6 (the 31khz ground wire) at the pcb.  I have the insturctions posted in the FAQ on this site http://www.arcadecontrols.com/arcade_consoles.shtml#dc2arcade.  I then hacked a VGA extension cable to get the R/G/B/H/V/Gnd and ran it directly to the inputs on my monitor.  I believe I tweaked the contrast slightly, but thats about it.  So maybe its your jamma board?

[unicron]

Hey people, I already said this a bunch, but if you get a black screen then you might just need to bleed off some of R G and B from your VGA box to your vga boxes ground, through some resistors.

I'm going vga box - jpac - jamma and I had that black screen too, but of course it whent away when I did that.

[JackTucky]

No, games like Gaunlet Ledgends will still have problems with the hacked VGA box.  BUT, there is a work around!  Most of these games  can be fooled by first booting up in "tv mode" and then switching it over to VGA mode after a couple seconds (approximately when the sega logo should be displaying).  I'm sure you've herd of this "switch method" to also get non-vga games to display in full VGA.

LOL.  I just started playing with my stand up dreamcast driiving cabinet with vga monitor and vga box, and I was going to post, "How come I can't play some games in VGA"

The switch method worked for me.  Why would they limit a game from VGA if it works fine?

Art

[Dave_K.]

LOL.  I just started playing with my stand up dreamcast driiving cabinet with vga monitor and vga box, and I was going to post, "How come I can't play some games in VGA"

The switch method worked for me.  Why would they limit a game from VGA if it works fine?

Art

It may be some sort of copyright/legal issue.  Maybe they want to insure its used on home TV's only (through composite or s-video).  Gauntlet will not work with a SCART rgb cable either (at 15khz) without the switch method.

The switch method still doesn't work on some games, like Bangai-O.  This game was specifally coded for a smaller frame buffer.