Broken to BBS: A Dell 286 Restoration [video]
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youtube.com
I wonder if there was some DOS driver already installed on the hard drive that allows "echo"ing text to a character device to make it say something - like he does at the end of this video, but unfortunately without an explanation of what the interface for that is.
edit: the longer video has a short bit at the very end where you can see some kind of menu system is launched from AUTOEXEC.BAT, with speech output. But it just cuts off after that - I'm a bit disappointed, since everything else is pretty much standard hardware for the time, while this card and the software supporting it is certainly rare, maybe even unique!