[SunRescue] Funkiness in Sparc serial consoles using vt100

[BSD Bob the old greybeard BSD freak]

> > I am running into a small problem on a Sparc Classic using a vt100
> > terminal (a real DEC VT420 in vt100 mode that works fine on VAXentoyz)
> > in that it has a propensity to add things like vertical bars and the
> > silly DEC ? chars (null?).  The thing is set 9600/8/n/1, and it works
> > fine on my SS10 running NetBSD or OpenBSD, but, on the Classic it
> > spits those chars.
> 
> I've seen the same thing on my vt420 with my IPX.  I haven't really
> nailed it down yet, but I have suspected it has to do with serial
> overruns.  My vt420 was in smooth scroll mode and I've turned it
> off and haven't seen it again (although I haven't used it much
> since I turned off smooth scroll).  I suspected an interaction
> between the smooth scroll and maybe me not having modem control
> lines right (got an IPX serial cable(sun) with a null modem to get
> output on the vt420).
> 
> That help?

In this case, no.  I am aware of the smooth scroll problem, but
this is not in smooth scroll.  Is there anything to do with signal
voltage levels that DEC uses vs Sun on the hardware?  Strange that
it works fine on the SS10, and not on the Classic.  I have seen it
on my IPX, too.  Is there some chip level oddity about it?
Anything in the prom settings that might affect it?

Thanks

Bob