Yeah, back in the bad old days of VAXen and COMETS. I once wrote an 80x24 character-mode simulator for COMETS to train new fab technicians and operators. It ran in an MSwin window(!)
Then we migrated to Sun servers running everything in the fab. The models that used our own CPU chips, of course. ("Eat your own dogfood.") And then when the Sun went down, we migrated to running all the fabs on ordinary Windows servers (and clients), typically Dell and HP last time I checked.