Question regarding use of monitor with BNC input on Prop.

Oldbitcollector (Jeff)

Got a couple monitors dropped off at my office tonight.

Two of them have both the standard "vga" connector, as well as 5 BNC connections.
R,G,B,HS.VS.

I've found cables which attach to these to connect to a VGA card.
Is there a chance I could feed a composite signal, maybe splitting the I/O lines
into R,G,B, and managing SYNC somehow, or am I dreaming here?

Thanks
OBC

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kwinn

I doubt you could use straight composite. Any monitor I have ever come across with separate BNC's for sync required TTL levels.

Kye

Hehe, yep your dreaming.

You can however pay $100 dollars to buy a device that will do that for you.

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Nyamekye,

agodwin

Some monitors with separate vertical and horizontal sync inputs will actually accept composite sync on just one of them. Try it.

Leon

It's sync on green, IIRC.

Leon

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ericball

Oldbitcollector said...
Got a couple monitors dropped off at my office tonight.

Two of them have both the standard "vga" connector, as well as 5 BNC connections.
R,G,B,HS.VS.

I've found cables which attach to these to connect to a VGA card.
Is there a chance I could feed a composite signal, maybe splitting the I/O lines
into R,G,B, and managing SYNC somehow, or am I dreaming here?

Thanks
OBC

First, search on the 'net for specs.· Depending on vintage the monitors may only accept one or a small number of frequencies & resolutions.· You also need to know whether the syncs are positive, negative, or can be combined in some way (i.e. combined sync or sync on green).· Often the BNC connections didn't provide any advantages over the VGA connector except for better cable properties.

Now, going from a composite (i.e. NTSC) signal to component (i.e. RGB+S) is a whole 'nother kettle of fish.· There are black boxes which do it (often not very well), but the bigger problem is the composite signal typically has sync frequencies to slow for a typical monitor.· Thus the black box is even more expensive 'cause it has to upconvert the signal.


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Toby Seckshund

If the monitors are pre VGA then CGA and EGA will run at NTSC sync rates of 15KHz and 60Hz. the syncs will have to be TTL levels, usually with about 1K Ohms loading. A sync sep chip would extract those. VGA monitors usually only go down to 31KHz and so would require up scaling.

If they are really top range and universal units then one of the sync inpits could be a combined one ie RGBS using 4 wires. Syncs on green would use composite levels ( 0.3 v ) under the green. Menu options may show this. Some medical grade units take almost every sort of input

Then there is the RGB or YUV options. Y is the total luninance signal of 0.7 V with 0.3 V syncs along with the colour difference signals. If you bet locked pics but they are very green or very magenta then its probably the wrong flavour.

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Style and grace : Nil point

Oldbitcollector (Jeff)

Reality hits again... Sheesh..

I need to find a monitor that support both VGA input as well as composite/S-Video.

Thanks for the answers guys. Even if they weren't what I wanted to hear.

OBC

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New to the Propeller?

Visit the: The Propeller Pages @ Warranty Void.