They have what are called "supertitles" [0] so that people can follow along with what the opera singers are actually saying. There is one on the back of each seat in the theater.
As near as I can figure, it's basically hundreds of LCD displays on some kind of bus network and connected to a computer via serial connection aka "D pin connector".
The software only runs on Windows XP and he has to keep finding old Windows XP machines on eBay in order to keep it working. I think he also has a couple hard drive images of the working OS + software.
I had suggested using a USB to D pin adapter and then use an LLM to sniff the protocol and then reverse engineer it.
His response:
"It HAS to work correctly. In 30 years we've never had an outage with the old system."