I change /etc/ttys and /etc/wscons.conf, i can't boot...!

[Luc DESFOSSES]

Hie, 

To try the 80x50 terminal, i've change the wscons.conf, and build the kernel 
with the good option.
It's works fine. but like i'm stupid, i uncomment de line #screen 0 and change 
the /etc/ttys.

i boot with boot netbsd -s, and i put the original ttys and wscons.conf

I can't boot, because when i log, each time i put key, i got a BIP, and nothing 
else.


If anybody can help me...! 
Thanks in advance...!