[rescue] Help with Wyse terminal

[Jeffrey Nonken]

I have here a WY-150 terminal that I either need to try to sell or
find a place for it in a landfill (or electronics disposal place or
whatever). It seems to work, at least it powers up and shows me a
status line, gives me quiet beeps when I press keys. I haven't really
gone beyond that because it seemed fruitless to prove that it
communicates serially if you can't change its parameters to something
useful.

The problem is that I can't seem to get it into setup mode. The
keyboard it came with is not the same model as any of the keyboards
they show in their online manuals. (Part No. 901879-01; model ANSI,
U.S./U.K., for whatever that's worth).

Christof says he's gotten it to work but doesn't remember how. Key
combinations like shift/select and ctrl/select don't work. Does
anybody have any idea what else I could try? I refuse to try all
possible key combinations, I need to finish the rest of my life doing
other stuff. :/

I'm hoping to tap into some arcane knowledge here. Maybe somebody
knows something that's not obvious. :)

Thanks for your time.