BNU
BNU is a high performance communications driver that supports most DOS based BBS software.
BNU was written as an experemental driver for serial communications, then being made
FOSSIL compatible, and was released to the public in 1989. Since then BNU has been one of the most widly used MS-DOS FOSSIL communications drivers.
A "FOSSIL" is simply a communications driver. It exists because MS-DOS and the IBM-PC BIOS provides very poorsupport for serial communications, and falls far short of the needs of any non-trivial communications task.
BNU was mainly used with DOS based
Bulletin Board System (BBS) Software written in the late 1980's to mid 1990's. It is not used by Windows based BBS software, but BNU can be used under Windows
NTVDM to run DOS based BBS software under Windows.