How do I get the console back on a SPARCstation?

[Tim Fredrick]

This is probably one of those questions that everyone but a brand new
SPARCstation user like myself knows, but without rebooting the system, how
can I restore my SPARCstation console so that it will accept logins.

The situation is that I am trying to figure out X-Windows and keep getting
either the console locked up so that it won't accept keystrokes, or into a
state where pressing any key results in several linefeeds being sent.  I
can use a remote terminal, but I need an easy way to restore the console
to the condition that it is in when you first start up the SPARCstation.

email replies will be appreciated.  Thanks.
  fredrick at acdpyr.ucar.edu