nmdm (4)

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	The FreeBSD Project

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(The comments found at the beginning of the groff file "man4/nmdm.4freebsd".)

NAME

nmdm - nullmodem terminal driver

SYNOPSIS

device nmdm

DESCRIPTION

The driver provides two tty(4) devices connected by a virtual ``null modem'' cable.

If either of the two tty devices have the CDSR_OFLOW bit (``stty dsrflow '' ) set in their line discipline, the device will emulate the speed configured in the termios(4) settings. The speed emulation works independently in the two directions, controlled by the slower end's termios settings ( c_ispeed , c_ospeed CS5 ... CS8 , CSTOPB and PARENB )

FILES

/dev/nmdm N [AB ]

nullmodem device nodes. Where the A node has a matching B node.

The driver implements ``on-demand device creation'' so simply accessing a given instance in /dev will create it.

DIAGNOSTICS

None.

SEE ALSO

stty(1), termios(4), tty(4)

HISTORY

The driver first appeared in Fx 4.4 .