To shead more light (hopefully), your SCO box
should already have "telnetd" (the telnet
server daemon) which can be "activated" typically
by adding (usually uncommenting) a line in
your /etc/inetd.conf file...
telnet stream tcp nowait root /usr/sbin/tcpd in.telnetd
...HOWEVER, if this machine is to be connected
to the internet in ANY way, I would recommend
AGAINST doing this as this will give a login
prompt to the telnet port 23 to anyone scanning
your IP address for that machine. In this case,
I would recommend OpenSSH (I recommend you use
SSH2 protocol as SSH1 is vulnerable without the
latest patches).
Additional info...
Windoze NetTerm client...
http://www.securenetterm.com/html/netterm.html
OpenSSH...
http://www.openssh.com/
A Windoze telnet/SSH client...
http://www.chiark.greenend.org.uk/~sgtatham/putty/
I hope this helps a bit