On Thu, 3 Dec 2020 at 21:15, <to...@tuxteam.de> wrote: > On Thu, Dec 03, 2020 at 08:35:37PM +1100, David wrote: > > On Thu, 3 Dec 2020 at 02:27, <rhkra...@gmail.com> wrote:
> > > I did find out that a USB-C cable / connector has 24 conductors -- so it > > > is > > > conceivable (with my lack of knowledge) that some laptop manufacturers > > > actually put out an (analog) VGA signal on the USB-C cable. > > Is this just wishful thinking or do you have evidence? > > Because it's inconceivable, as far as I'm aware. Everything I have read > > about USB-C indicates that it is purely digital. Even though it seems > > to be the USB way to have countless variations of every physical and > > electrical specification, VGA is a standard from 1987, forget finding > > it on any USB-C connector. Those pins are all used for other things. > USB-C is a mess. Quoth [1]: > > "A device with a Type-C connector does not necessarily > implement USB, USB Power Delivery, or any Alternate Mode: > the Type-C connector is common to several technologies while > mandating only a few of them" > > That said, Display Port, Thunderbolt, MHL and HDMI alternate modes seem > to implement VGA output with an "active" cable, which is an euphemism > for "there's some chips in there". > > So your computer's USB-C socket must fit, your dongle, aka "active > cable" must fit, and they have to be capable to talk to each other. Does the active cable have a USB-C connector on the VGA end? The comment I responded to speaks of analog VGA signals on a USB-C connector. I thought "that's weird" so before I wrote I had a quick read of all the main links under the heading https://en.wikipedia.org/wiki/USB-C#Alternate_Mode_partner_specifications and I saw no trace of any such thing. As always, I'm happy to be corrected if wrong. I take no interest in "active cables" myself, modern passive cables are unreliable enough, but if someone wants to provide a link then I will enjoy a chuckle that someone somewhere thinks this is good engineering.