This would not have wholly worked with Linux. As I've noted elsewhere in this discussion, Linux does not support all of the Unix mechanisms. It does not implement the XCASE line discipline flag; so, unlike on Unix, on Linux one cannot use the xcase mechanism to get lowercase on an uppercase-only terminal.

FreeBSD doesn't support the Unix mechanism, either. Nor does NetBSD.

Xe could have connected it to an OpenBSD system. OpenBSD still supports the whole mechanism.

* https://github.com/openbsd/src/blob/57d747eef2b80ca9ffb95407...