Converting 4 BNC RGB+Sync to VGA or RGBHV HOw?

[rmay635703]

Hi, I have a proprietary graphics system that sends out RGB graphics via a 9pin port. It can be converted to 4BNC RGB + Sync w/ a targa cable I have. I am looking for a way to separate the sync so I can hook up a standard VGA monitor as the monitors for this unit are getting harder to find.

I have looked long and far and everything (you can buy) seems to convert VGA output to 4 BNC but not the other way around.

I was told on the repair website (before it dissappeared) that a few vga monitors could take the syncs combined on the H channel but which ones?

Any ideas?

[KachiWachi]

Do you mean Composite Sync? "Composite Sync is what happens when the horizontal sync signal and the vertical sync signal are combined into the one "composite" signal. This works because the vertical sync pulse is much longer than the horizontal sync pulse and there are no horizontal sync pulses required during the vertical sync period. This requires only one wire for both the sync signals." (Plagiarized from the net...my apologies to the author.)

Is this what you are looking for?? - http://www.covid.com/Signal/COV7905.html

[rmay635703]

Yes that is exactly what I am looking for. My system sends composite sync. (no idea why) But it hooks into a 9pin magnavox RGB monitor that is similar to vga in res and color depth but of coarse takes composite sync.

Hmm, thats a little pricey compared to the vga converters I have seen, too bad there isn't a simplified "home" version that only has 3bnc's 1 in 2 out

Originally I was thinking of building my own but given I don't know exactly the type of signal is coming out and what to separate it into I'm a little stuck, I haven't been able to find the usual build your own schematics so I don't have to do any actual designing.

I will bookmark that page in case my monitor blows up and use this as a last resort.

Cheers

[KachiWachi]

All I did was put "Composite Sync" into the IE search feature...and there it was.

Maybe you can get something from this page, which also came up in the search... http://www.hut.fi/Misc/Electronics/circ ... 2rgbs.html .

[soupy]

Let me see if I have this straight.

Currently, you're running 9-pin to 9-pin. Look like this?



You want to convert 9-pin to HD15 to attach a standard monitor? Maybe a DB9 to HD15 cable, then a Sync Separator, then a HD15 to HD15 cable?

You also have a 9-pin to 4BNC, but you can't find a VGA monitor that will accept the Composite Sync?

Here's a list of monitors with 4BNC inputs:
http://www.si87.com/Support/monitordb.html

What's the name of the hardware, by the way?

[rmay635703]

Kachi
I came up with pages like that before, but now how do I get it to go the other direction? (I am only an IE sorry If I attach composite sync on the opposite end it doesn't seem to work backwords.
http://www.hut.fi/Misc/Electronics/circ ... 2rgbs.html .

Soupy

Yep, thats one of the cables I have 9pin to 9pin monitor cable, the other is 9pin to 4BNC

When I attach 4bnc to a vga monitor that is so equipt it always has 5bnc's and displays an image but of coarse it isn't sync up right due to the lack of the other cable.

I do have 9pin to 15pin converters BUT and this is very very important the pinout is unknown of the video output and the pin converters I have must be for CGA not RGB analog as I just get a horrible red/black flashing screen if I attach this unit to a vga monitor.

The hardware we are talking about is a QLT or CASI Tech Futura 100 graphics computer. The graphics card is by Omnovion Corp 1990. Which sends out 16.8million colors at 640x ??? resolution. The monitor for the machine I believe is a Magnavox RGB analog CMI1432 ??? but I will have to go home to find out for certain what model. Its one of the last RGB screens made and had RCA, TTL, RGB, CVBS, etc etc connections and had built in stereo sound.

I seem to remember the 4 BNC adapter is called TARGA if that means anything.

Cheers
Ryan

[soupy]

When I attach 4bnc to a vga monitor that is so equipt it always has 5bnc's and displays an image but of coarse it isn't sync up right due to the lack of the other cable.

So I guess you haven't been able to try a monitor with 4BNC, then? You might be able to dig up some used models from that list.

The NEC MultiSync XL (JC-2001VMA) has both 4BNC and DSUB9 connections; it might work. You can probably pick up a used one fairly cheaply too.
http://www.griffintechnology.com/archiv ... NEC33.html


Heh...
http://www.justfotos.com/uequip.htm

[KachiWachi]

Maybe try searching for "Sync Seperator".

I'm sure you can find something that works on a TV set and apply it here. I did find a chip that can strip out the composite and vertical sync from a video signal, but not both H and V seperate. But I only looked quickly (National LM1881 $1.35 USD http://www.national.com/pf/LM/LM1881.html ). In your case I would think that the video area would not be included in the sync signal, but the chip would still be able to seperate out what it can from that.

Combining the signals sure is easier !!

Good luck hunting!!

[cake]

Is this what you're looking for?

http://www.hut.fi/Misc/Electronics/docs/pc/vga2bnc.html

or you might find the info you need here

http://www.epanorama.net/links/pc/video ... onnections

[rmay635703]

Hmm, those sites are usefull, but alas they all have info on going the wrong direction VGA->BNC I need the other way around.

[KachiWachi]

Try this... http://www.msxhans.msx2.com/pdfsdiy/msx2vga.pdf

[rmay635703]

Thanx KachiWachi, now the fun part

Cheers
Ryan