cty.4

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 4 代码 · 共 41 行

.\" SCCSID: @(#)cty.4	3.1	11/24/87
.TH cty 4 VAX
.SH Name
cty \- extra serial line interface
.SH Description
.NXR "cty keyword"
.NA "console interface" "serial line interface"
.NXR "serial line interface" "adding"
The extra serial lines are available to the processor through the
console registers. These lines are available on the VAX 8100, 8200,
8300, 8500, 8550, 8600, 8650, 8700, and 8800 machines and number three
all total.
They act like normal terminal lines, except for the VAX 8600 (8650), where
the first line can also act as a remote console port and the other two
lines are currently unused. Entries for these lines should be placed
in 
.PN /etc/ttys ,
if they are used.
.PP
There are also certain workstation configurations that
may use the console serial interface.  For MicroVAX workstation 
configurations, calling 
.MS MAKEDEV 8
with the argument ttycp will create the device special file needed to 
utilize the console interface.  
Before using the serial line interface, it is important to consider the
setting of the halt enable switch on a MicroVAX workstation.
.PP
.SH Restrictions
In general, the lines are low-performance devices.
They can be used as terminal ports, but, for each character
sent or received, the CPU is interrupted. Thus, it is
recommended that the extra serial lines
be used at low baud rates (2400 baud or less), 
so that console input and output do not severely impact system
performance.
.SH Files
.PN /dev/ttyc?
.SH See Also
console(4), tty(4), MAKEDEV(8)