mdc.4

<B>Digital的Unix操作系统VAX 4.2源码</B>

.TH mdc 4 RISC
.SH Name
mdc \- DS5100 serial line driver
.SH Syntax
.nf
.B "device    mdc0     at ibus?     vector mdcintr"
.B "device    mdc1     at ibus?     vector mdcintr"
.B "device    mdc2     at ibus?     vector mdcintr"
.fi
.SH Description
.NXS "mdc interface" "DS5100 serial line interface"
.NXR "DS5100 serial line interface"
A DS5100 base system (mdc0) provides four asynchronous ports.
An optional asynchronous card (mdc1 and mdc2 ) can be added to supply 
eight additional ports.
.PP
The 
mdc 
ports are used as follows:
.PP
.ta \w'Port    'u +\w'full modem control port    'u 
.nf
\f(HBPort	Usage	Connector\fR
.sp
0	Console port	6-pin MMJ on CPU board
1	Local terminal	6-pin MMJ on CPU board
2	Full modem control port	25-pin D-Sub on CPU board
3	Local terminal	6-pin MMJ on CPU board
.sp
An optional asynchronous board provides an additional eight lines:
.sp
4	Local terminal	6-pin MMJ
5	Local terminal	6-pin MMJ
6	Full modem control port	25-pin D-Sub 
7	Local terminal	6-pin MMJ 
8	Local terminal	6-pin MMJ
9	Local terminal	6-pin MMJ
10	Local terminal	6-pin MMJ
11	Local terminal	6-pin MMJ
.fi
.PP
The console baud rate is set to 9600 baud by default. 
You can change this 
by setting the baud environment variable from console prompt.
Each communication port from the serial line controller
behaves as described in the
.MS tty 4
reference page and can be set to run at any of 16 speeds. 
For the encoding, see
.MS tty 4 .
.PP
You can establish the state of port 2 (port 6) by specifying either
modem or nomodem as part of the 
.PN /etc/ttys 
file entry.
.SH Restrictions
The speed default is to 9600 baud on the console port.
The console device must be set for 8-bit character 
length with one stop bit 
and no parity. The 
.PN mdc 
driver enforces these restrictions; 
that is, changing speeds with the 
.PN stty 
command may
not always work on console ports.
.SH Files
.TP 20
.PN /dev/console
Console terminal
.TP
.PN /dev/tty??
Full modem control or local terminal
.SH See Also
console(4), devio(4), tty(4), ttys(5), MAKEDEV(8)