Another tip, you need to a special adapter to go from VGA to HDMI as well.

Chaining VGA <-> DVI <-> HDMI also won't work.

DVI does have the option for VGA, it's the 4 pins around the flat blade connector. It's just that almost nobody implements it

It used to be very common.

DVI-* is also a great example of how to handle compatibility.

A DVI-I to VGA adapter will not physically fit into a DVI-D socket. Because it won't work, so it doesn't have the holes.

DVI-D and HDMI 1.2* are actually exactly the same, the only difference is the licence fee.

(I think it's 1.2. Might be 1.1)

DVI-D and HDMI 1.2* are actually exactly the same, the only difference is the licence fee.

and the fact that you don't get audio over a DVI connection, whereas you can with HDMI.

M.

Yes, but that doesn't help you if the output device doesn't do analogue.

-A.

DVI ports can carry both analogue on the bladed pins, as well as digital on the pinny pins. You can then take VGA from a DVI and HDMI from DVI, but HDMI and VGA are two rather different things, hence you need an extra adapter from HDMI <-> VGA.

Mostly. For computer graphics and no audio HDMI / DVI are equivalent (except you don't have to pay the HDMI licence fee for DVI)

For video HDMI can do more high bit depth modes and of course has sound

By using Thunderbolt cables instead? Since Thunderbolt uses the same connector, and supports the highest speeds, wouldn't they be a superset of all that USB-C nonsense? Or is there is a gotcha in there? I'm guessing there's a gotcha in there, because there's no way the USB standards people want to make ANYTHING easy!

No. Thunderbolt requires support on both ends. If you use a Thunderbolt cable and one of the sides doesn't support Thunderbolt, then you will have a problem. At least some cables will have a fallback USB connection, but I think that's optional and it certainly won't use the faster Thunderbolt connection if your USB would support faster speeds than the fallback wire does. It might not work at all, and if it does, you won't be guaranteed any speed advantages for doing it.

I'll agree with the point that HDMI to DP adapters aren't cheap. I have a couple of them and there were on the order of $30 each. They're also hard to find, mostly because when you try to look them up you get vast numbers of DP to HDMI adapters and very few HDMI to DP. What I'd love to see would be decent ones made that work both ways. Like wise for conversion between VGA and HDMI.

And, yes, my HDMI to DP adapters are for Pis connected to original PackedPixel monitors that only have DP. However since PackedPixel went over to HDMI (at least as an option) and then proceeded to go out of business, they're not a long term plan. Fortunately, there are now more and more companies putting portable monitors on the market that use HDMI input. Basically laptop displays packaged with a power supply and a cover, and for a lot less money.

What I'd love to see would be decent ones

There is plenty of decent video conversion kit out there, but you do end up paying for it, for example [1]Kramer AV and [2]Blackmagic .

Those tend to concentrate on broadcast formats, so Displayport and DVI are thin on the ground. Canford have been around since I was in primary school and have a range of [3]video converters from various manufacturers, for example [4]Muxlab . I dare say there's other stuff out there.

I use a lot of Pis, but with large monitors and projectors which feature multiple inputs, so connection is no problem. The biggest issue I had recently was the need to use a Pi to play video on an honest-to-goodness old black-and-white portable TV. As the Pi has a composite video output (you try finding one of those on a graphics card these days) all I had to do was plug it in to an RF modulator. It even gave the visitors the genuine experience of knocking the large tuning dial (no buttons on this TV) and being met with snow and white noise. Surprising how many adult staff couldn't work out how to retune the set!

One of the reasons some converters might be more expensive is if they include the ability to scale the input to suit the output. For example, it's no good expecting to be able to convert 4k HDMI to VGA without downsizing it a bit. Converting to DisplayPort probably requires some quite hefty processing as, while most formats (e.g. HDMI) send a continuous stream of pixel data, DisplayPort is some kind of packetised system so that video data can be sent along the same wires as network or audio or, well, whatever I suppose.

M.

[1] https://www.kramerav.com/products

[2] https://www.blackmagicdesign.com/products/miniconverters/models

[3] https://www.canford.co.uk/Video-interfacing-processing-monitoring-and-camera-accessories

[4] https://www.canford.co.uk/MUXLAB-VIDEO-CONVERTERS

One would generally expect older slower kit to work on newer faster incarnations of the same interface.

Like USB, for instance. Once you've navigated the maze of different interface types and managed to electrically connect the two, a crappy USB 1.1 MIDI adapter (the sort that shits itself if you play two chords at once) will work on a USB 3 port. I also have an old computer with 10baseT plugged into the ADSL box with 100baseTX equipment and it just works (but obviously is notably laggy to that one device).

Whilst Ethernet negotiates itself from low to very high, USB 1-2 and USB 3+ are actually separate buses. You could have a port that supports only USB 3+ and not USB 2-.

Things get even muddier when using adapters. I have a Samsung S8 that seems to have a not uncommon problem whereby it detects liquid if charging with a C-A cable and refuses to charge. Works perfectly with a C-C cable.

Techmoan recently posted a video where he also found some Minidiscs refused to work with some software when plugged into an A port (USB-A devices), but worked fine when using an A-C cable plugged into a USB-C port (still using the USB-A bus on the host side).

I guess I'll just carry on using my existing gear then. That said, I have one of those Plugable 4K laptop docks, and the ethernet adaptor is pretty useless with three monitors hogging the bandwidth.

I know nothing about this stuff beyond articles like that that I don't understand. BUT, the whole USB thing sounds like a total muddle of incomprehensible and unrecognisable inconsistency.

Aargh!

This is like OS/2 version 3, but worse. Which version is it, exactly?

USB 4 version 2.

Is that version 4.2? Or what?

-A.

"You can connect any HDMI display to a Displayport connector..." - Not exactly- it needs to be a dual mode DisplayPort https://en.m.wikipedia.org/wiki/DisplayPort#DisplayPort_dual-mode_(DP++).

Back in the day God (USB Forum) created USB, which then had two flavours - low speed and full speed. Both being USB 1 - woe betide you got confused with a USB 1 peripheral/hub that wasn't what you expected. Then came USB 2, using the same cables/ports, but with a new colloquial name High Speed. Then came USB 3 with a same-looking USB-A connector (with more pins and typically blue), along with USB-C ports.

Then came a plethora of things using the USB-C port, but offering a multitude of different capabilities, USB3, USB4, Thunderbolt... Not necessarily a bad thing, but if you have a port supporting one of these, it's not instantly clear what subset of features your port has. Some laptops only allow charging on one of the USB-C ports just to confuse things more. If your device has multiple USB-C ports, why should they not all be identical?

To me it seems a mess, I mean it's nice that you can use the same USB-C port for charging the device as well as charging devices from it. Using the same ports for Thunderbolt - if they support it, but the naming conventions just seem wrong. Not that I have any better ideas though :)