About 7 years ago, I was a word processing clerk for the American Psychological Association. Their mainframe software, and presumably the mainframe itself, dated from 1977. And the dumb terminals were so old, they were encased in wood! The only way I know this is from one that had a chipped corner. The cases appeared to be plastic, but they were really wood! Yes, the APA has since replaced their entire network with WinNT.