tty console locking up on Sun-4's?

[Leonard Sitongia]

Have those of you who do *not* use bitmapped displays on your Sun-4's
noticed any peciliarities regarding the console locking up?  I've been
trying to port the "assassin" (idle terminal killer, author: Charles
Sandel) to Sun-4 / OS 4.0 and it works just fine on two Sun-4's with
various hardware configs, but both having bitmapped displays.  However, on
another Sun-4 with a terminal on ttya as the console, the program causes
the console to lock up, then any program (like syslogd) that wants to
write to the console will cause a "BAD TRAP / DATA FAULT" system crash!

vmunix: BAD TRAP
vmunix: assassin: Data fault
vmunix: kernel read fault at addr=0xc, pme=0x0
vmunix: Bus Error Reg 80<INVALID>

I am still digging into VAX-to-SPARC porting issues, but thought I'd check
if there are any hints out there.

Thanks,
Leonard