.\" Copyright (c) 1983, 1991 Regents of the University of California.
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.\" 3. All advertising materials mentioning features or use of this software
.\" must display the following acknowledgement:
.\" This product includes software developed by the University of
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" @(#)dmz.4 6.4 (Berkeley) 3/27/91
.Cd "device dmz0 at uba? csr 0160540" "vector dmzrinta dmzxinta dmzrintb dmzxintb dmzrintc dmzxintc"
device provides 24 lines of asynchronous serial line support.
Modem control on all ports is available
as an option for the H3014 distribution panel.
may be supplied with the device specification for
in the config file indicating
that the line corresponding to
connected, and should be treated as hard-wired with carrier
always present. Thus specifying
to be treated in this way.
control parameters for individual lines are managed by
Line speeds (there are 16 choices for the
or may be communicated by other programs which
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.
.Bl -tag -width /dev/tty[abcefg][0-9a-n] -compact
.It Pa /dev/tty[abcefg][0-9a-n]
within a timeout period. This is often followed by a
error. This occurs most frequently when the
and when devices which hog the bus (such as
.It dmz%d: silo overflow.
The character input silo overflowed
before it could be serviced. This can happen if a hard error occurs
is running with elevated priority, as the system will
then print a message on the console with interrupts disabled.
It should be possible to set the silo timeout with a configuration file option,
as the value is a trade-off between efficiency and response time for flow
control and character echo.
projects / unix-history / blob