Running the "service service_name status" command gives three different types of output when three different service_names are used. I tried with atftpd, apache2, and isc-dhcp-server, as shown below.

user@host:~$ service atftpd status
Usage: /etc/init.d/atftpd {start|stop|restart|reload|force-reload}
user@host:~$ service apache2 status
Apache2 is running (pid 1103).
user@host:~$ service isc-dhcp-server status
isc-dhcp-server start/running, process 5696

Could this be because atftpd has not been converted to Upstart?

The status for isc-dhcp-server shows "start/running" which indicates it has been converted to use Upstart. I would've thought apache2 would have been converted to Upstart already. If it has then why does it not display "start/running"?