Supporting IBM line drawing set on QNX 6 console

We have some old text mode screens that use what may have been called the IBM line drawing characters. They’re in the ASCII set around 0xC0, 0xC1, etc…
With QNX 4, we were able to use the TERM=QNX console but on QNX 6 consoles these characters aren’t displayed. We’ve tried several console settings without success. Does anyone know how to support these characters under QNX 6?