This isn’t really true. The old terminal monitors are essentially dumb CRTs and the the museum pieces are just displaying the output from a regular PC running the modern app converted to an appropriate signal + BNC connectors so you see something and not just a black screen.
The old terminal hardware communicated over dedicated serial lines and worked in conjunction with many other “server-side” pieces of software that no longer exist, so it would be impossible to make one function as it did back in the day.
The old terminal hardware communicated over dedicated serial lines and worked in conjunction with many other “server-side” pieces of software that no longer exist, so it would be impossible to make one function as it did back in the day.