Dreamcast VGA question....

[Truecade]

So I purchased an original DC VGA box so I could hook this thing up to a computer/arcade monitor.  For some reason, it won't work with my 17" CRT monitor or my 19" LCD monitor.  However, it does work perfectly with my D9200 arcade monitor.  When I hook it up to my computer monitors I just get a black screen.  I read somewhere that the DC VGA only works with monitors that accept VGA signals, and some computer monitors only accept SVGA. 

What gives?  Are my monitors non-compatible or did I get a bum VGA box? 

Has anyone else had this problem hooking up a DC to their computer monitor?  Thanks in advance.

[Dave_K.]

Can you check what frequency the D-VGA box is outputting when it works on your d9200?  It should work with LCD monitors or standard PC monitos, its just 640x480 at 60hz.  Are you sure the switch is set to "PC" and not "TV"?

[JB]

I read somewhere that the DC VGA only works with monitors that accept VGA signals, and some computer monitors only accept SVGA. 

That's insane.

I find it VERY hard to believe that someone would make a monitor that won't accept 640*480@60. On every version of Windows(as an OS) before XP, safe mode was that res and refresh rate precisely BECAUSE that's the only guaranteed supported mode. I've got no idea what XP does for safe mode.
e dom efas

[Marky_1979]

is it possible to get the vga box to support higher than 640x480 ? say 800x 600 or higher?

[Minwah]

is it possible to get the vga box to support higher than 640x480 ? say 800x 600 or higher?

Don't think so.  Personally I think the DC looks better on a TV (via RGB) than on a PC monitor anyway...I know some people disagree 

[Marky_1979]

Me and a friend actually had this same argument it got to the point where we actually set up 3 dreamcast one on scart one on normal av lead and one on a pc monitor and vga box. The 3 control test games where chu chu rocket, virtua sriiker 2 and sonic adventure.

Vga kicks ass followed closely by scart the av was awful picture was blury and very poor quality.

[Truecade]

Can you check what frequency the D-VGA box is outputting when it works on your d9200?

[Minwah]

Vga kicks ass followed closely by scart the av was awful picture was blury and very poor quality.

I still disagree.  IMO the crispness of the VGA makes some games (certain objects or textures) look worse.  Basically the same principal as why I prefer to play MAME games on an arcade monitor to pc monitor - pc monitors are too 'good'!

Agreed composite video is crap tho

[Dave_K.]

Vga kicks ass followed closely by scart the av was awful picture was blury and very poor quality.

I still disagree.  IMO the crispness of the VGA makes some games (certain objects or textures) look worse.  Basically the same principal as why I prefer to play MAME games on an arcade monitor to pc monitor - pc monitors are too 'good'!

Agreed composite video is crap tho

Minwah, remember what we are talking about here.  A DC is really Naomi hardware.  The games are perfect Naomi ports, which were made to be played at 31khz on a Sega Naomi Cabinet.  So these games were made with 640x480 in mind.  Completely different than Mame games which were all made for std resolution.

[Lilwolf]

Run the dreamcast on a true arcade CRT. 

I don't believe you get any better then this.  I think it looks much better then the vga myself...   And SVID also... never tried the others.

[Minwah]

Minwah, remember what we are talking about here.  A DC is really Naomi hardware.  The games are perfect Naomi ports, which were made to be played at 31khz on a Sega Naomi Cabinet.  So these games were made with 640x480 in mind.  Completely different than Mame games which were all made for std resolution.

Yeah I know what you're saying is right.  But I still reckon they look better at 15khz...640x480 looks too sharp to my eyes.

[gnateye]

either your box is fried or someone already shorted it to display on arcade monitors, but it sounds fried

[P.H.U.]

Dude, your box is kaput.  Did you buy it used?  Sounds like you picked up a used VGA box that was already hacked for 15 khz  .  And whoever owned it previously must have also cut the 6th wire from the other (wrong) side as well. 

If you count over 6 pins from the left with the VGA box connector turned pins up and facing you, then the 15 khz pin is 6th from the left.  And if you count 6 pins from the right, guess what?  It is the S-Video output.  Coincidence that your S-Video is kaput too?  I think not.  If you didn't buy it used, you bought a previously returned product pawned off by your retailer as new.

Do yourself a favor and go to www.jandaman.com and get one of their two VGA solutions, either the cable or the box.  Both are great.  I run all 4 of my 15khz cabs with them (combination of 2 cables and 2 boxes) and I have another VGA box hooked up to my PC monitor for good measure!  Did I say that both are just under $9 and $10 respectively.  The last order I placed with Jandaman was shipped to me in less than 5 days (Sat and Sunday was inbetween) and I bought 2 VGA cables, a VGA box, and a Joybox.  Shipping was just over $4.  US based, rock bottom prices for the VGA box, and no mark up on USPS Priority shipping.  You can't go wrong.

Ok, Jandaman owes me some kick back now!  j/k.  More than happy to give exuburent praise when I am a satisfied customer!!!!!

[WTB]

I've never had any problems with my VGA box and my opinion is that VGA rules. I also vote that your box was mis-cut and/or fried. And all I have to say to you PHU is... Damnit! Why the hell did I pay $30 bucks with shipping for mine.  Awesome link, I'll definitely be giving them some business. Thank you!

   -Matt

[P.H.U.]

I've never had any problems with my VGA box and my opinion is that VGA rules. I also vote that your box was mis-cut and/or fried. And all I have to say to you PHU is... Damnit! Why the hell did I pay $30 bucks with shipping for mine.  Awesome link, I'll definitely be giving them some business. Thank you!

   -Matt

Yeah, I know the feeling.  Sorry WTB.  But do send them some business and keep them afloat, will ya!

Now if only I can convince Dave_K to update this site's FAQ and point out to folks that instead of opening the box and running the risk of snipping the wrong wire, you can also count 6 pins over from the left with the connector turned pins up and facing you, prop up the 6th pin, and break it off with needle nose pliers, we may never see another DC VGA hack post/question again!  Reason being various brands of boxes are constructed differently and across different brands it is harder to distinguish what is the appropriate 15 khz ground wire even with a multimeter.  Heaven forbid those that don't even have multimeters!  Of course the drawback would be absolutely no 31 khz output with that VGA box/cable again, but that is ok.  Not all of us have dual-rez arcade monitors .

C'mon Dave!  I can post pics if you want.

[Dave_K.]

PHU, nice to see you posting here  .  I still thinking breaking off pin #6 on the dc-connector end is rather harsh, but agree it is simple and sure fire.  I should at least update the FAQ to mention that you cannot trace pin#6 with a multimeter since both 6 and 7 are tied together at the PCB.  So at most, people with a multimeter should be able to narrow down pins 6+7 on the PCB, and have a 50/50 chance of cutting the correct wire.  I really don't like having to swap out VGA boxes when one is permananetly hacked to 15khz (like I have now)...so installing the toggle switch would be a benifit for people who even just want to go back to a PC monitor.

[elvis]

I still disagree.  IMO the crispness of the VGA makes some games (certain objects or textures) look worse.  Basically the same principal as why I prefer to play MAME games on an arcade monitor to pc monitor - pc monitors are too 'good'!

Agreed composite video is crap tho

Gotta agree with you.  SCART and 15KHz RGB monitors are almost like a free anti-aliasing/blending.  Some games just look too blocky and perfect on a VGA monitor.  Older monitors add just the right amount of "fuzz" to a picture to make it that much more authentic.  I've got a 21" PC monitor in my first MAME cab, and the picture is certainly great, but not as appealing as looking at the real deal on my 25" JAMMA cab.

Of course, games that are *designed* for VGA or greater look bloody fantastic on VGA hardware.  Funny that.   But then again, I actually play very few 3D games on my DC.  I mostly play 2D fighters.

Back on topic: On dreamcast CGA/VGA: if both pins 6 and 7 are grounded, a 31KHz signal is output.  If only pin 7 is grounded, 15KHz is output.

Easiest thing to do is add a simple 2-way switch on the pin6 line to ground.  Not a hard mod at all, and gives you simple 15/31KHz control from the flick of a switch.  As mentioned, get a multimeter out and test your vga box for the problem.  Shouldn't be a hard fix at all, as there's no complex circuitry thanks to the DC spitting all this stuff out natively.