RGB, VGA on my TV?

[ken_cinder]

Wondering what I'm going to require to get RGB outputs on my consoles working on my TV. I'm still learning here, but I think I've got a bit of a handle on it.

Can I wire up RGB to the VGA input on my TV, IF it supports 15khz on that input? I assume this is a pre-requisite.
My TV is an Acer AT3220A, and I haven't been able to dig up any useable info on it's technical specs, but I'm willing to hack things up a bit and test.

Be even better if someone could find papers on my TV, so I can see just what I'm capable of doing via it's available inputs.

[Lost Monkey]

I've been wondering the same about mine - the user manual indicates that it would accept 15khz on the "PC" port, but when I quickly hacked together a Genesis cable, I got no results - just black screen. I haven't had time to go back and experiment with it again...

The tv is a Panasonic TH50PX600.

[movax]

Your horizontal frequency has to be able to sync down to 15kHz. Even then, you still need to feed the display via whatever interface it uses, I believe R, G, B and then Sync...either H/V Sync or C Sync. The latter can be obtained from a Composite Video signal and a LM1881N, and there's probably a way to do C Sync to separate H/V sync.

Of course, some consoles also provide separate H/V Sync lines.

[Endymion]

Can I wire up RGB to the VGA input on my TV, IF it supports 15khz on that input? I assume this is a pre-requisite.
My TV is an Acer AT3220A, and I haven't been able to dig up any useable info on it's technical specs, but I'm willing to hack things up a bit and test.

You are correct, this is exactly what you need. I doubt anybody here will have the same television that you do but if anybody does and they read this thread I'm sure they can respond with their experiences. Roll back your sleeves and search, google is your friend.

Lost Monkey, I have a Panasonic TH50PHD8UK. Its manual states it accepts 15KHz RGB over the DSub that accepts VGA (31KHz +) as well and it works without issue. In fact it even accepts sync over green. Is your screen an HDTV monitor? If so, it will probably even accept RGB (15KHz) and VGA (31KHz +) over the BNC lines as well.

[ken_cinder]

So I should be able to do it straight up (Wired directly to a 15 pin D-Sub) if the console has seperate H+V available to tap, but if not I'm going to have to build a circuit to seperate H+V from C-Sync.

Am I following correctly here?

[Endymion]

Presuming your TV cannot accept composite sync over the DSub, yes. Sounds like you know what you are doing, just find out from the manufacturer what the TV can do, that is the only missing information here. Some sets (like mine) can take both.

[Lost Monkey]

Lost Monkey, I have a Panasonic TH50PHD8UK. Its manual states it accepts 15KHz RGB over the DSub that accepts VGA (31KHz +) as well and it works without issue. In fact it even accepts sync over green. Is your screen an HDTV monitor? If so, it will probably even accept RGB (15KHz) and VGA (31KHz +) over the BNC lines as well.

I will have to give this another go on the weekend - I would be absolutely giddy if I could get RGB up on this panel -

Mine (being a NA model) doesn't have BNC connectors - just the DSub in addition to the HDMI, component, s-video, composite and RF...

BTW - as an aside - the Dreamcast looks absolutely stunning through the VGA box on this TV.  I had it connected to a 21" Viewsonic monitor before (which shit the bed last summer) which was gorgeous, but there is nothing like Soul Calibur on a 50" display....

[Endymion]

My unit is a North American/NTSC as well, it's just a plasma "monitor" from the professional line, the component input comes in over BNC. Panasonic makes the best plasma money can buy and this one's been very versatile for me. It is configurable enough that I'm not lacking anything from my CRTs, but I don't know how this translates to their consumer line.

[ken_cinder]

Ok after finally getting the parts I needed in, I wired my new Taito F3 system up to the VGA port on my LCD HDTV. What do you know, it works!

I have a couple issues though.

1: Some of the colors look washed out. Is this need for some resistors on the RGB lines? If so, what should I use?

2: My sync appears to be ever so slightly off. With the clock at default, theres ALOT of flicker, thankfully I can adjust the VGA clock on my TV, so upping it fixes it for the most part, but theres still a bit of flicker, mainly at the edges. I tried throwing the 47uf capacitor inline on sync that I had on my PSOne LCD, but this causes the TV to not even detect a signal. Lower rated capacitor? Something else?

I don't have anything shielded yet mind you, it's all bare wires from the jamma harness to the bare solder VGA connector. Shielding an issue in correcting the 2nd issue maybe?
Here's some pics, if you know Puzzle Bobble 2, you'll know that the colors in some spots are WAY off, but in others are perfectly correct.

[s8n]

hi IJTF_Cinder , are you the same Cinder that is into Dreamcast ?  ie  associated with DC++ hubs etc......

either way what up and good luck , i have a similar project with the LM1881N Dreamcasts PS2s Gamecubes and a Sega New Astro City.

do you know KillerCabs Forums ?..........maybe sign up and ask the same question about ' Washed Out '......


s8n

[s8n]

Cinder if you had a dark image people usually insert ' Caps ' on the RGB lines to brighten up the picture........i havent heard of people using them for ' Washed Out Colors ' but maybe its worth a shot ?

i use 220uF 16V Radial Electrolytic Caps on my RGB lines.

[s8n]

i use this LM1881N circuit for my project

http://www.mameworld.net/pc2jamma/arc_dc4.html

[acem77]

the vga port on my samsung dlp worked using this set up.
not all systems worked that great . some better than others.
i would highly recommend a xrgb2 plus(other xrgb devices should work).
i am very happy i did, nothing else i have tried looks as good.
so far it works with the most systems and arcade pcbs.
its well worth the money.
search around you will find some post from me with pics.

[Endymion]

Great that it synced right up for you, this will make your work a lot easier from the get-go. You probably do need a buffer of some kind, and in almost every instance of this I see posts here from the man that solves the issue. Say his name and he will surely appear.

Viletim, paging viletim.

[blackevilweredragon]

Cinder if you had a dark image people usually insert ' Caps ' on the RGB lines to brighten up the picture........i havent heard of people using them for ' Washed Out Colors ' but maybe its worth a shot ?

i use 220uF 16V Radial Electrolytic Caps on my RGB lines.

I wonder if putting caps on the Mac mini's VGA out will brighten it's picture up too..

Rev A Mac mini's like mine, have low contrast outputs, and actually have some interfearance too..

[ken_cinder]

Cinder if you had a dark image people usually insert ' Caps ' on the RGB lines to brighten up the picture........i havent heard of people using them for ' Washed Out Colors ' but maybe its worth a shot ?

i use 220uF 16V Radial Electrolytic Caps on my RGB lines.

Capacitor wasn't on my color lines, it was on my sync line. My PSOne LCD had a bit of an issue with the sync, and a 47uf ceramic capacitor did the trick.

My colors are washed out, almost like they're far too bright at some points, which is why I asked if resistors would be a good idea. I have no problems with the brightness of the colors, where they appear correctly that is.

[viletim]

When you connect such a signal to a TV set the resault is uaualy a super high contrast picture. In the case of you your LCD monitor, the signal will probably be clipping at the A/D converter. Different symptom but the solution is the same. Always put resistors in series with the video when connecting arcade boards to non-arcade monitors! Experement to find the best value for your particular board - 100 ohms is a good starting point.

[ken_cinder]

Thanks viletim, I must be learning something from you guys if I had the right idea.

Now to piss the wife off some more with hacked up projects lying around on the dining room table. hehe

[ken_cinder]

Awesome, I threw some 100ohm resistors on the color lines, and it's alot better now. I think I'm going to swap them out for 150's though, as the contrast is still a bit too high.

Any ideas on my other issue? I'm still getting a slight issue of the edges tearing and what appears to be faint rolling lines down the screen. Pop a lower rated capacitor on the sync line? Something like 10/22uf?

Edit: Here's some pics, with 150ohm resistors. I ran MAME, and the colors match up perfectly, so I think I'm good there. As for the tearing, I'm not sure what to do, using a cap doesn't seem to be the answer, as I've tried 7uf all the way to 221uf with no result (Any capacitor causes the display to not detect). I even thought maybe the sync signal was slightly too high, so I threw a 10ohm resistor in, then a 100, then a 150....nothing, no change.