HDMI - VGA mystery cable

[GS3]

Rummaging through crates of cables of all sorts I found a cable with HDMI connector on one end and VGA on the other end. I have no idea how this thing came to be in my possession.

HDMI and VGA are totally different video standards and there is no way they can be interfaced without some electronics in between but these connectors look like standard connectors which would have no space for any electronics. It does have one of those ferrite anti-interference sleeves but it is molded into the cable and not inspectable. I suppose there is a small chance it is not really a ferrite filter at all but an advanced electronic video converter circuit.

I am trying to think how to best test this thing.

It could be just some crazy direct connect cable which could damage my computer and my monitor if I connect them using this cable.

It could be that plugged into an HDMI video output it would convert it to VGA and I could connect it to a VGA computer.

Or it could be the other way around and it would convert a VGA signal to HDMI for an HDMI monitor.

There is no way to tell because both HDMI and VGA cables have the same connectors at both ends.

I would like to determine what it is but without taking any risks of damaging my working machines.

What say you?

[absque fenestris]

...
What say you?

That it is a mystery to me why analog VGA is installed at all... the oldest standard I use is now DVI-D - (Digital Visual Interface).

The last time I used VGA cables was with old Macs and old cathode ray tube monitors - before the disposal ...

[Portreve]

What say you?

---

In all seriousness, GS3, I think you have it surrounded. DVI was the last standard to have support for analog (DVI-A) so there's clearly something else going on there. Here's an example of a pretty unassuming looking converter cable.

[kelevra]

...
What say you?

That it is a mystery to me why analog VGA is installed at all... the oldest standard I use is now DVI-D - (Digital Visual Interface).

The last time I used VGA cables was with old Macs and old cathode ray tube monitors - before the disposal ...

I have an old HP/Compaq 6305 with DP and VGA outputs. I tried the DP, using a DP-HDMI adapter, with my older BENQ monitors (1680x1950) and only got a garbled output. So I dug out one of my old VGA cables that came with the monitors and voila, working monitors. And yes the adapter works, I hooked up the computer to a 4k TV and it worked at 4k and 1080p.

I would like to determine what it is but without taking any risks of damaging my working machines.

What say you?

As to the OPs question, I don't know if something like that is bi-directional. Wouldn't something inside the adapter fail before anything connected to it?

My sister just cleaned out her truck and found a HDMI-component adapter. She used it for the kids when they travelled for 4H and high school rodeo. I think she said it was for a second monitor on a portable DVD player so the kids didn't fight over the who got the display in front of them. I have an old 12" portable DVD player that is usable as a monitor, I was going to test the adapter and see if works on my laptop to have a second display. I am not sure if it is bi-directional, I hope I don't wreck anything as well.

[GS3]

In all seriousness, GS3, I think you have it surrounded. DVI was the last standard to have support for analog (DVI-A) so there's clearly something else going on there. Here's an example of a pretty unassuming looking converter cable.

Yes, like that one. It is amazing they can fit all the electronics needed for the video conversion in the molded connectors.

For now I am going to assume mine converts an HDMI output from a computer to VGA for a monitor and I will give it a try when I get a chance of doing it without too much risk to property, life or limb.

One thing that I do not understand is that I suppose the audio signal in the HDMI is lost and the user needs to get the audio separately.

A comment by the way: the link you provided has all sorts of identifying information about your session. Everything after the question mark is information about your personal session with that site and it is good practice to strip the link naked of session info and send only the base link which in this case is

Code: Select all

https://www.walmart.com/ip/Ielectr-EDAL-1-8-M-HDMI-Cable-HDMI-To-VGA-Adapter-Digital-1080P-HD-With-Audio-Converter-Adapters-HDMI-VGA-Connector/894860717]https://www.walmart.com/ip/Ielectr-EDAL-1-8-M-HDMI-Cable-HDMI-To-VGA-Adapter-Digital-1080P-HD-With-Audio-Converter-Adapters-HDMI-VGA-Connector/894860717

and even that one can be shortened to https://www.walmart.com/ip/894860717 and it will work just fine.

I wish browsers could do this automatically. Besides "copy link" there should be the option "copy link stripped of session info" or something similar.

[GS3]

As to the OPs question, I don't know if something like that is bi-directional. Wouldn't something inside the adapter fail before anything connected to it?

I am quite sure it is not bidirectional.

When I was a kid and learning about the way things worked in this world which was new to me I learned that if I saw someone in a mirror they could see me because the the process was "reversible"; the light from me bounced in the mirror and went to them but the light from them bounced back to me. It took me some time to realise that TV did not work the same way and the people who appeared on the screen could not actually see me.

I might be forgiven because I was only a kid but I once had a boss who had an AC adapter which took mains power and output 12 VDC and he told me he was afraid to connect it to the car battery because it could be that if disconnected from the mains it might take the 12V from the car and output high voltage at the other end. I had to explain that there was no risk of that because it was not "symmetrical".

I do not think an HDMI to VGA converter would work the other way around. I mean, I suppose it could be possible to make a bidirectional one which would first detect where the signal is coming from but I do not think it is commonly used or available.

[GS3]

That it is a mystery to me why analog VGA is installed at all... the oldest standard I use is now DVI-D - (Digital Visual Interface).

The last time I used VGA cables was with old Macs and old cathode ray tube monitors - before the disposal ...

All my computers and monitors have VGA and it works fine and it is the most reliable. I have tried HDMI and other combinations and sometimes got something to work but it was such a complication it was not worth it. I remember in one particular case the computer would only boot in VGA and then I could switch to HDMI. No thanks.

At any rate, as I said, I found this cable and do not even remember where it came from. Probably one of my friends who, like me, hates throwing anything away so he gave it to me. I have crates full of stuff my friends threw away by giving them to me. Sadly I do not have friends I can give junk to.

[RollyShed]

That it is a mystery to me why analog VGA is installed at all... the oldest standard I use is now DVI-D - (Digital Visual Interface).
The last time I used VGA cables was with old Macs and old cathode ray tube monitors - before the disposal ...

Dozens of computers running VGA. This one has VGA and DVI-I monitors connected. My partner, two DVI-D. A laptop has VGA or HDMI available. Another has micro HDMI and the 3rd one only has VGA. Dataprojectors, VGA. There are some with Displayport around just to totally upset things.

VGA is not dead.

[Portreve]

A comment by the way: the link you provided has all sorts of identifying information about your session. Everything after the question mark is information about your personal session with that site and it is good practice to strip the link naked of session info

Well spotted!

Yeah, I was in my phone doing that and in a bit of a rush, so I didn't do any cleanup. Ordinarily I do.

[GS3]

There are some with Displayport around just to totally upset things.

I have some HP-Compaq computers with DisplayPort connector but it is so-called DisplayPort Dual Mode which will output HDMI if I connect a passive DP to HDMI adapter or cable.

Reading that Wikipedia article I now see that works but only in one direction so the monitor can receive video from the computer but the computer cannot receive feedback from the monitor and maybe that is why I needed to boot in VGA first and then I could change over to HDMI (from the DP).

[absque fenestris]

That it is a mystery to me why analog VGA is installed at all... the oldest standard I use is now DVI-D - (Digital Visual Interface).
The last time I used VGA cables was with old Macs and old cathode ray tube monitors - before the disposal ...

Dozens of computers running VGA. This one has VGA and DVI-I monitors connected. My partner, two DVI-D. A laptop has VGA or HDMI available. Another has micro HDMI and the 3rd one only has VGA. Dataprojectors, VGA. There are some with Displayport around just to totally upset things.

VGA is not dead.

Of course, I see that VGA is still used everywhere. What amazes me, however, is that despite all the digital outputs, there is apparently only one analog video standard from 1987 that people & industry really agree on.

As you can see - also here in the Mint forums - HDMI and DisplayPort doesn't really work foolproof - but it's no wonder with all the different versions and very questionable cable offerings.
DVI-D seems to work best of all digital video outputs (... my experience on Mac, Windows & Linux). Of course, it's no longer installed on new devices.

And we can look forward to USB-C/Thunderbolt version xyz, where everything will be much, much better, faster, easier and nicer...
...except those with AMD..

[Portreve]

Of course, I see that VGA is still used everywhere. What amazes me, however, is that despite all the digital outputs, there is apparently only one analog video standard from 1987 that people & industry really agree on.

Technically, it's not VGA; it's SVGA. But yes, sometimes the only solution is to kick it old school. Now, when we see a Hercules or a CGA standard being used, then we're kicking it old school alpha foxtrot.

VGA is not dead.

[absque fenestris]

...
Technically, it's not VGA; it's SVGA. But yes, sometimes the only solution is to kick it old school. Now, when we see a Hercules or a CGA standard being used, then we're kicking it old school alpha foxtrot.
...

That is exactly what I checked before sending my post, whether I should speak of VGA or SVGA.
Since everyone is talking about VGA, I left it at that (and SVGA is not much younger either ... )

[Portreve]

That is exactly what I checked before sending my post, whether I should speak of VGA or SVGA.
Since everyone is talking about VGA, I left it at that (and SVGA is not much younger either ... )

I have no idea exactly when it started, but at some point in the (I think) late 1990s or very, very early 2000s, people stopped referring to SVGA as SVGA.

SVGA uses a DB-9 sized 15 pin interface, whereas VGA used a proper DB-9 (which is to say, 9 pin) interface. All Macintoshes¹ from the Mac II and SE (ca. 1987) until the last platinum case G3 tower and desktop models used graphics cards with DB-15 connectors. The "Bondi Blue" G3 towers and original era iMacs were the first models² to use the industry standard (by then) SVGA port. However, Apple had determined that the step up from 640×480 would be 832×624 instead of the industry standard 800×600. They felt it represented the user interface better. Eventually, both 832×624 and 800×600 were supported.

---

¹ This is a very confusing situation by present day (i.e. 2021) standards. Technically, no Macs "came with" 15-pin graphics ports until the Mac IIci, and even then most still didn't until the LC-series and Quadra- and Centris-series. It was expected that people would use the internal video (for all-in-one models such as the SE, SE/30, Classic, etc.) unless they wanted to use an external monitor, in which event they would buy a separate graphics card, just as their Mac II, IIx, IIcx, IIfx (and so forth) brethren had to do because there was no onboard graphics card.

² There was, technically, nothing stopping graphics card makers from making a graphics card for a Mac and using either a DB-9 or an SVGA port. Towards the end of the era, most card makers either did that or provided (or you could buy separately) an adapter. However, Apple as well as 3rd party card makers used Apple's port instead because all Apple monitors and most monitors made for the MacIntosh market used the DB-15 port.

[absque fenestris]

...Macintoshes from the Mac II and SE (ca. 1987) until the last platinum case G3 tower and desktop models ....

If you're talking about the 90s Macs and VGA/SVGA: for non-Mac CRT monitors you always needed some weird converter/adapter with several jumpers (Mäuseklavier...) for the resolution settings and something with Sync on Green.
Can you tell me the English name of this part?

[Portreve]

...Macintoshes from the Mac II and SE (ca. 1987) until the last platinum case G3 tower and desktop models ....

If you're talking about the 90s Macs and VGA/SVGA: for non-Mac CRT monitors you always needed some weird converter/adapter with several jumpers (Mäuseklavier...) for the resolution settings and something with Sync on Green.
Can you tell me the English name of this part?

OMG, I forgot all about that! Yes, the term we've always used is "DIP switch" (or switches, for the plural form).

For anyone who's curious, this is what absque fenestris and I are talking about. Not all adapters came with DIP switches, but those which did provided them for compatibility.

[absque fenestris]

Merci meint Dankeschön in the french part of CH

[Portreve]

Merci meint Dankeschön in the french part of CH

Thanks for that, absque! I haven't thought about any of this in probably 15 or 20 years (if not longer than that) so this has been a real trip down memory lane.

I know there's often discussion about how things were better in the old days, but all I have to say to that is: BULLCRAP!!! There were so many complexities associated with getting anything done, and I for one appreciate the streamlining effects of standardization. Yes, there still are a few port standards, but for like 90% of use cases, just use HDMI. (Or, in a different discussion, just use USB 3.)

The old days will always occupy a special place in my heart, but just like an automotive enthusiast who might drool over a Model T Ford, while I might miss my Mac Plus (or Mac II, or Mac IIci, etc...) those are things which properly belong in a museum, not on somebody's actual work desk.

P.S.: Ich kann ein bisschen Deutsche sprechen. Ich brauche (und will) es mehr zu studieren.

P.P.S.: I have the boxed set of Michel Thomas Teaches French. That's because French is on my list of things I want to learn, but also because it will make finishing my 2 year college degree a lot easier.

[ivar]

That it is a mystery to me why analog VGA is installed at all... the oldest standard I use is now DVI-D - (Digital Visual Interface).
The last time I used VGA cables was with old Macs and old cathode ray tube monitors - before the disposal ...

Dozens of computers running VGA. This one has VGA and DVI-I monitors connected. My partner, two DVI-D. A laptop has VGA or HDMI available. Another has micro HDMI and the 3rd one only has VGA. Dataprojectors, VGA. There are some with Displayport around just to totally upset things.

VGA is not dead.

.. and then add Mini DP, micro DP, mini HDMI, micro HDMI to the list of needed cables/adapters..

At work we've been running Lenovo's only for the last 5 years. The desktops got DP , which works with all 4 standards without a hitch.
The laptops - not so fun. Our lenovos docks got several different combinations of the 4 outputs. But they can very picky at which combination of outputs that will work in a dual monitor setup. For the least problems, we've found that one of them has to be VGA.

Reading that Wikipedia article I now see that works but only in one direction so the monitor can receive video from the computer but the computer cannot receive feedback from the monitor and maybe that is why I needed to boot in VGA first and then I could change over to HDMI (from the DP).

Interesting - could explain some of our issues with dual monitor setups mentioned above.

As you can see - also here in the Mint forums - HDMI and DisplayPort doesn't really work foolproof - but it's no wonder with all the different versions and very questionable cable offerings.
DVI-D seems to work best of all digital video outputs (... my experience on Mac, Windows & Linux). Of course, it's no longer installed on new devices.

In my experience, HDMI is by far the most troublesome. Cable failure is not uncommon.