NOTE: This driver has not been ported from
4.4BSD yet.
The
dmz device provides 24 lines of asynchronous serial line support. Modem control on all ports is available as an option for the H3014 distribution panel.
An optional argument
flags may be supplied with the device specification for
dmz in the config file indicating that the line corresponding to bit number
i is not properly connected, and should be treated as hard-wired with carrier always present. Thus specifying ‘flags 0x000004' for
dmz0 would cause line
ttya2 to be treated in this way.
Normal I/O control parameters for individual lines are managed by
ioctl(2) calls. Line speeds (there are 16 choices for the DMZ) may be initiated via
getty(8) and
stty(1) or may be communicated by other programs which use
ioctl(2) such as
ifconfig(8), see
tty(4).
The
dmz driver normally enables the input silos with a short timeout (30 milliseconds); this allows multiple characters to be received per interrupt during periods of high-speed input.