oh my, out of boredom, I searched Yahoo! for Excelsus! BBS and found someone mentioned it in forum in 2003!
http://www.clinteastwood.org/forums/index.php?topic=1199.0
Excelsus BBS ran on an Atari 520STfm and then an Atari 1040STf from 1988-1992. 1st only on single sided, 360K 3.5" floppy (BBS software AND data!) then ended up on a 50MB hard disk. It was actually one of the 1st (maybe THE 1st) BBS in Hampton Roads, Virginia to have blazing fast 2400baud access. Only had 1 phone line the entire time.