dc.4

<B>Digital的Unix操作系统VAX 4.2源码</B>

.TH dc 4 RISC
.SH Name
dc \- serial line/mouse/keyboard
.SH Syntax
.B "device	dc0	at ibus?	vector dcintr"
.SH Description
.NXR "serial line controller" "dc"
.NXR "dc serial line controller" 
The serial line controller provides four ports, with 
modem control on two of the ports.  The DECstation 3100 and DECstation 2100
only provide partial modem control.  The DECstation 5000 provides full
modem control. The ports are used as follows:
.sp
.nf
\fBPort\fR      \fBUsage\fR
.br
0         Graphics device keyboard at 4800 BPS
1         Mouse or tablet at 4800 BPS
2         Communications port 1 (w/modem control)/local terminal
3         Communications port 2 (w/modem control)/local terminal
.fi
.PP
Each communication port from the serial line controller
behaves as described in
.MS tty 4
and can be set to run at any of 16 speeds. 
For the encoding, see
.MS tty 4 .
.PP
When a graphics device is not being used as the system console, communications
port 2 becomes the system console.  In this configuration, the port can only
be used at 9600 BPS and no modem control is supported.
.PP
The serial line driver operates in interrupt-per-character mode
(all pending characters are flushed from the silo on each interrupt).
.SH Restrictions
Speed must be set to 9600 BPS on the console port and 4800 BPS on ports 
used by graphics devices.  The serial line driver enforces this restriction; 
that is, changing speeds with the 
.PN stty 
command may not always work on these 
ports.
.SH Files
.TP 20
.PN /dev/console
console terminal
.TP 
.PN /dev/tty00
local terminal
.TP 
.PN /dev/tty01
local terminal
.SH See Also
console(4), devio(4), tty(4), ttys(5), MAKEDEV(8)