Hi
The adapters are very easily obtained at low prices and my experience
is that they work if you got them from CPC. I have used them.
John Eayrs
On Sat, 27 Feb 2016 15:04:29 +0000
Ben Parsonage <ba.parsonage@???> wrote:
> My understanding is that you will need an active adapter.
>
> The vga protocol is an analogue display protocol that is designed to
> drive a crt display directly (ignoring some amps) . The protocol has
> a few clocks (such as pxclk , lsp, vsync etc...) as well as rgb
> intensity (3 signals) and positioning which drives x,y mag fields for
> the electron deflection.
>
> DVI, HDMI and display port are all digital protocols. They deliver a
> header along with what is essentially a rgb bitmap as well as some
> clocks and power. There is also some generic signaling possible for
> things like copy protection and remote command pass though.
>
> Because the standards are so similar the devices can find a common
> signal level protocol so passive adapters are possible but only at
> the lowest quality of the source, sink, and both interfaces. All will
> do 1080p@60Hz. There may be some requirement to level shift on the
> electrical level and obviously a change has to be made at the
> mechanical level.
>
> DVI (but not dual link DVI) also has a legacy analogue mode which
> allows it to be connected via a passive adapter to a vga port. This
> functionally is a feature of dvi and going dp>dvi>vga won't work as
> there is no way for the signal to be created. Similarly HDMI as a
> "media" (and not display) protocol includes a digital audio line but
> any set up which is not pure HDMI will not have this functionality.
>
> Ben
>
> ==============================
> This is a summary some aspects are intentionally wrong in order to
> simplify, other areas may be incorrect due to my ignorance or poor
> memory. This has been written all from memory with no sources if this
> information is mission critical or you just don't like being wrong
> you should cross check, look up format specs on the net or go to the
> library (the one in the centre is quite good). I provide this
> information in good faith but accept no responsibility for action
> taken due to it ;-) . ==============================
>
>
>
> On 27 February 2016 13:21:53 GMT+00:00, "Chris. Aubrey-Smith"
> <cas194@???> wrote:
> >My understanding is that rather more is required to achieve the
> >digital/analogue conversion.
> >
> >Chris
> >
> >
> >
> >On 27 February 2016 at 13:06, john <jee@???>
> >wrote:
> >
> >> Hi
> >>
> >> My Understanding is that HDMI is VGA plus audio. So HDMI to VGA
> >should
> >> work fine. Only difficulty is that some adaptors have difficulty
> >with
> >> plug and play detection, but that is not a problem because you can
> >set
> >> the VGA size in the computer.
> >>
> >> John Eayrs
> >>
> >> On Sat, 27 Feb 2016 07:17:06 +0000
> >> Lisi Reisz <lisi.reisz@???> wrote:
> >>
> >> > Jeffrey Best will be talking to us about ""Developing a CouchDB
> >> > Application Using CouchApp"?, about which more anon. But
> >meanwhile,
> >> > we have a connection problem. Jeffrey has a laptop with a
> >> > DisplayPort port. He also owns an HDMI adapter for it. So we
> >> > need to be able to adapt: ideally, DisplayPort to VGA for the
> >projector;
> >> > failing that HDMI to VGA, but I have an inbuilt unease about a
> >> > -> b -> c adaptation. Too much to go wrong! So can anyone help
> >> > with DisplayPort to VGA? And a backup of HDMI to VGA? It would
> >> > help if solutions are known to work. Jeffrey himself has in
> >> > fact got a DisplayPort to VGA adapter, but it doesn't work in
> >> > practice.
> >> >
> >> > Jeffrey will bring his presentation on a USB stick in case , so
> >could
> >> > we be sure to have at least one laptop running LibreOffice
> >> > Impress, with an ability to connect to VGA.
> >> >
> >> > All help and suggestions welcome. If DisplayPort is the future,
> >this
> >> > problem will arise again, so we need a solution.
> >> >
> >> > I was thinking of buying this for the group:
> >> >
> >>
> >http://www.amazon.co.uk/DisplayPort-Display-Adapter-Convertor-Macbook/dp/B017Q8OCSY/ref=sr_1_16?ie=UTF8&qid=1456556516&sr=8-16&keywords=DisplayPort+to+VGA+adapter
> >> >
> >> > until I saw this:
> >> > "Didn't work on my set-up, but this due to DP/HDTV not the cord
> >> > itself. I needed active adapter I eventually sussed." in the
> >reviews.
> >> >
> >> > So: comments? Advice? Has anyone got an "active adapter"?
> >> >
> >> > If nothing else offers, I'll get two adapters - DisplayPort to
> >> > VGA and HDMI to VGA and hope for the best!
> >> >
> >> > Lisi
> >> >
> >> > Lisi
> >> >
> >>
> >>
> >> --
> >> Please post to: Hampshire@???
> >> Web Interface:
> >> https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL:
> >> http://www.hantslug.org.uk
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> >>
> >
> >
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