.TH SCC 3 
.SH NAME
scc, duart, uart \- serial communication control
.SH SYNOPSIS
.nf
.B bind -a #t /dev

.B /dev/eia0
.B /dev/eia0ctl
.B /dev/eia1
.B /dev/eia1ctl
.fi
.SH DESCRIPTION
.PP
The serial line devices serve a one-level directory,
giving access to the serial ports.
There are several devices serving the same files;
the particular one used depends on the machine involved.
.B Eia0
is a stream data file.
It can be read and written to use that port.
Reads will block until at least one character is available.
.B Eia0ctl
is a stream control file associated with the port.
.B Eia1
and
.B eia1ctl
are similar, but for a second serial line.
.PP
The
.B ctl
file can be used to push stream modules onto the port.
One can also write one of the following textual commands to a
.B ctl
file:
.TP
.BI b n
Set the baud rate to
.IR n .
.TP
.BI d n
Set DTR if
.I n
is non-zero;
else clear it.
.TP
.BI k n
Send a break lasting
.I n
milliseconds.
.TP
.BI r n
Set RTS if
.I n
is non-zero;
else clear it.
.TP
.BI m n
Obey modem CTS signal if
.I n
is non-zero;
else clear it.
.TP
.BI p c
Set parity to odd if
.I c
is
.BR o ,
to even if
.I c
is
.BR e ;
else set no parity.
.TP
.BI s n
Set number of stop bits to
.IR n .
Legal values are 1 or 2.
.TP
.BI l n
Set number of bits per byte to
.IR n .
Legal values are 5, 6, 7, or 8.
.SH SOURCE
.B /sys/src/9/port/devscc.c
.br
.B /sys/src/9/*/devduart.c
.br
.B /sys/src/9/*/devuart.c