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 <[email protected]> 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" > <[email protected]> wrote: > >My understanding is that rather more is required to achieve the > >digital/analogue conversion. > > > >Chris > > > > > > > >On 27 February 2016 at 13:06, john <[email protected]> > >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 <[email protected]> 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: [email protected] > >> Web Interface: > >> https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: > >> http://www.hantslug.org.uk > >> -------------------------------------------------------------- > >> > > > > > >------------------------------------------------------------------------ > > > >-- > >Please post to: [email protected] > >Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire > >LUG URL: http://www.hantslug.org.uk > >-------------------------------------------------------------- > -- Please post to: [email protected] Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --------------------------------------------------------------
