Attaching a Display

Code & Zahlen

Personally and professionally I have seen my fair share of display connectors. At this point it has a Kafkaesque complexity. At the theory department we have computers ranging from around 2006 to current ones. This means that we also have all kinds of display connectors on the workstations and tablets:

  • DisplayPort, VGA
  • VGA
  • DVI-I
  • DMS-59
  • DisplayPort, HDMI, VGA
  • DisplayPort, HDMI
  • Mini-DisplayPort
  • Mini-DisplayPort, VGA
  • DisplayPort, VGA
  • HDMI, VGA
  • Mini-HDMI
  • Micro-USB

People also bring their laptops from home, so this is an additional source of connectors. Now we have various types of displays that one wants to connect to:

  • DisplayPort, DVI, VGA
  • DVI, VGA
  • VGA
  • HDMI, VGA
  • SCART

For this purpose I have a bunch of adapters that accumulated over the years:

  • HDMI → DVI
  • DVI → VGA
  • DisplayPort → DVI
  • DMS-59 → DVI-I
  • DMS-59 → VGA
  • Micro-USB → HDMI
  • DisplayPort → HDMI

Unfortunately VGA seems like a rather solid option because it is so compatible with various things. It is an analog signal, so text will be a bit blurry, one has to let the display auto-adjust to map it onto the pixels and it just does not make sense with a digital panel and a digital graphics card. I would really like to not use that at all, but somehow it turns out to be the fallback surprisingly often.

Sometimes one needs to daisy chain some adapters to attach a screen, take for instance this ridiculous setup:

Another time I wanted to attach my laptop (sporting DisplayPort and VGA) to a TV screen supporting HDMI and VGA. Yes, one could just have used VGA and have a crappy image at 1920×1080. Instead we used one DisplayPort → DVI cable and another DVI → HDMI cable to make it work. The GPU in my laptop likely did the DVI compatibility mode on the DisplayPort port and the TV did the DVI compatibility mode on its HDMI port.

Perhaps even funnier was attaching an Android tablet to the projector. The tablet has Micro-USB and the projector just VGA. There is a Micro-USB → HDMI adapter for the tablet, but it is an active one. So one needs to attach another Micro-USB cable to the adapter to provide power. The other side of the power cable of course had USB-A. Then we used another HDMI → VGA adapter to actually attach the projector.

USB-C somehow promises to unify all this mess. But already there is the DisplayPort alternate mode, there is the HDMI alternate mode for USB-C. One cannot tell by the connector which ones are supported now, and in which version. Then one needs to have a beefy cable which actually supports the amount of data which is transferred there. Basically one will be no better off but just has an additional option.

Having DisplayPort and HDMI in parallel seems like a really bad idea. I realize that DisplayPort is the successor for DVI and therefore addresses computers. And HDMI is the successor for SCART and therefore addresses multimedia equipment like TVs. But these days TVs are just really large displays, there is no need for a different connector. People also want to connect their laptops to their TVs. It seems that consumer hardware has focused on HDMI whereas business hardware has DisplayPort. But businesses buy projectors with HDMI because people bring consumer laptops.

I wonder how long into the future I will continue to attempt to attach some display in a digital fashion, realize that I lack some adapter to make it work, weep a bit and just use VGA.