BNU is a high-performance communications device driver designed to provide enhanced support for serial port communications. The BNU serial port driver was specifically targeted for use with early (late 1980s - 1990s) DOS-based BBS software. The reason for BNU and other similar enhanced serial port drivers was to provide better support for serial communications software than what was offered by the machine's BIOS and/or DOS being used on the machine. Having serial port support as provided by BNU and other similar drivers allowed the communications software programmers to spend more time on the actual applications instead of the depths and details of how to talk to the serial ports and the modems connected to them. Sending communications data across a modem link was a lot more involved than