Dreamcast VGA cable to DVI-I?

Post by **sideshow** » Sat Mar 03, 2007 10:14 pm

I just bought a decent projector that supports 720p resolution natively. What I want to do is hook up my dreamcast to it via the dreamcast VGA cable yet my projector doesnt have a VGA input(15 pin). Instead it has DVI-I and HDMI inputs. Would it be possible to hook the dreamcast via the VGA cable directly into the DVI-I input and get 480p quality?

Post by **sideshow** » Sun Mar 04, 2007 1:26 am

Ok, I got assistance from another forum. It appears if your HDTV, Projector, whatever has a DVI-I input then all you need to do is buy a $4 VGA (Male) to DVI-I (male) converter for the Dreamcast VGA cable and the connection is made with no loss in video.

Post by **racketboy** » Sun Mar 04, 2007 9:38 am

Did anybody you talked to actually try it to confirm?

Post by **sideshow** » Sun Mar 04, 2007 4:23 pm

No, but it seems legit cause I did some research on VGA and DVI-I and both are analogue. Well, DVI-I is both analogue and digital its just a newer technology format that HDTV's are pushing nowadays. DVI-I pin setup is just different than the 15 pin D sub plugs that VGA use. I havnt actually tested it yet but I will in a couple weeks once I get my projector. I did buy the converter from Newegg and its only $4 and I bought the VGA cable from you racketboy so I'll put it to the test soon.

I actually bought the wrong adaptor for my setup. Since the Dreamcast VGA cable end is female and my projectors DVI-I input is female also, you need a male to male adaptor. I see one on the projectors site that is 20 bucks so not too bad.

Post by **racketboy** » Mon Mar 05, 2007 8:10 am

sideshow wrote:No, but it seems legit cause I did some research on VGA and DVI-I and both are analogue. Well, DVI-I is both analogue and digital its just a newer technology format that HDTV's are pushing nowadays. DVI-I pin setup is just different than the 15 pin D sub plugs that VGA use. I havnt actually tested it yet but I will in a couple weeks once I get my projector. I did buy the converter from Newegg and its only $4 and I bought the VGA cable from you racketboy so I'll put it to the test soon.

I actually bought the wrong adaptor for my setup. Since the Dreamcast VGA cable end is female and my projectors DVI-I input is female also, you need a male to male adaptor. I see one on the projectors site that is 20 bucks so not too bad.

Well, the reason I ask is I know that a simple VGA-to-Component cable won't do the trick for the Dreamcast. You need something that actually converts the signal. Not sure if this is the same case.

Post by **sideshow** » Thu Mar 08, 2007 1:07 am

Yes, I believe VGA and Component video works differnt so you would need a transcoder to do the conversions. VGA and DVI-A or DVI-I is the same type of video just different pin layout. I will post my results as soon as I get all my gear. Here is some info on the differences of VGA (RGB) and Component (YPbPr).

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

And here is some info on DVI:

http://www.datapro.net/techinfo/dvi_info.html

I'm not the complete wizard on all the technicallities of these formats but I'm positive I dont need to do any transcoding/processing from VGA to DVI-A. The projector I bought even has in the manual a picture showing a RGB cable being hooked up to the DVI-I input by means of a simple pin converter.

I just cant wait to play all those great shmups on the dreamcast in VGA! I've only played Psyvariar 2, Under Defeat, Ikaruga, etc. by means of composite so this is a HUGE upgrade for me.

Post by **sideshow** » Fri Mar 23, 2007 1:52 am

Well, I finally got my projector and hooked up the Dreamcast via VGA to DVI-I. The projector gives me this reading when hooked up, "640x480 60 Hz". I'm not quite sure if this is 480p? When I hooked up PS2, XBOX, 360 to it via component, the projector reads 480p, 720p, etc. The picture looks amazing but I'm not quite sure if its outputing 480p for the Dreamcast?

Post by **metaleggman** » Fri Mar 23, 2007 2:20 am

sideshow wrote:Well, I finally got my projector and hooked up the Dreamcast via VGA to DVI-I. The projector gives me this reading when hooked up, "640x480 60 Hz". I'm not quite sure if this is 480p? When I hooked up PS2, XBOX, 360 to it via component, the projector reads 480p, 720p, etc. The picture looks amazing but I'm not quite sure if its outputing 480p for the Dreamcast?

Well, be assured that is 480p. The reason is because it's prolly thinking it's computer output, so it wants you to know which resolution the computer is outputting so you can get the correct resolution. I wouldn't worry about it.

Also, the reason VGA->Component won't usually work (depends on the "component" as there is a RGB variant me thinks) is because VGA is RGB and Component is YUV. The reason this worked is because DVI-I is DVI-A and DVI-D. The DVI signal allows for a digital channel, but also has pins for a normal RGB channel as well. This is why no converter is required.

Post by **sideshow** » Fri Mar 23, 2007 12:07 pm

I was leaning toward that the output is 480p. Thanks for the information.

Post by **lordofduct** » Fri Mar 23, 2007 12:53 pm

racketboy wrote:
sideshow wrote:No, but it seems legit cause I did some research on VGA and DVI-I and both are analogue. Well, DVI-I is both analogue and digital its just a newer technology format that HDTV's are pushing nowadays. DVI-I pin setup is just different than the 15 pin D sub plugs that VGA use. I havnt actually tested it yet but I will in a couple weeks once I get my projector. I did buy the converter from Newegg and its only $4 and I bought the VGA cable from you racketboy so I'll put it to the test soon.

I actually bought the wrong adaptor for my setup. Since the Dreamcast VGA cable end is female and my projectors DVI-I input is female also, you need a male to male adaptor. I see one on the projectors site that is 20 bucks so not too bad.

Well, the reason I ask is I know that a simple VGA-to-Component cable won't do the trick for the Dreamcast. You need something that actually converts the signal. Not sure if this is the same case.

First off Metaleggman has it right on the DVI-I thing... DVI-I and DVI-A carry the VGA signals in it along with the Digital ones, this is why it works. The device will use the Digital before the analog, but if no digital is present it then uses the analog.

As for the VGA to component cables. Those cables aren't converters, an actual converter box is required which turns the RGB signalling into YUV and then drops the sync onto the luminance signal. Those straight VGA to component cables are a miscommunication in description.

See before the 'component cable' we know and love for our HDTVs became big, RGB was the talk of the videophile town and came in a marriad of variants including VGA. Each had different cables that went with them. A good collection of them came on RCA cables and others on BNC connectors. Because these cables had all the wires seperate (as opposed to VGA which had all its wires wrapped in a big thick plastic tub and one connector) they called these seperate wires component. Merely because component is a word meaning "a constituent part; element; ingredient"... or parts.

So when YUV component cables came out it just adds even more annoyances in naming their products. But basically here in America you should always assume that if it ISN'T VGA or an old Apple II then component RGB is not supported.