Visit Our UNIX and Linux User Community

Linux and UNIX Man Pages

Test Your Knowledge in Computers #414
Difficulty: Easy
JavaScript is a high-level, interpreted scripting language that conforms to the ECMAScript specification.
True or False?
Linux & Unix Commands - Search Man Pages

ports(7) [osf1 man page]

ports(7)						 Miscellaneous Information Manual						  ports(7)

ports, port_names - Device (tty and lp) names for serial and parallel ports SYNOPSIS
Default Serial Ports: /dev/tty00 /dev/tty01 (not present on a single-port system) Parallel Port: /dev/lp0 DESCRIPTION
AlphaStation and AlphaServer systems provide one or two 9-pin serial communication ports. These ports are usually labelled 1 (COMM1) and 2 (COMM2), but they may be identified by different icons. Using the appropriate serial cable and terminator, you can connect a serial printer, external modem, or character-cell terminal to a serial port. Most AlphaStation and AlphaServer systems also provide one parallel port, for use with a parallel printer. When you add a device to your system, the installation documentation may instruct you to map the device pathname to the port. These devices are located in the /dev directory. For serial-line ports, the two default device pathnames are: This pathname always maps to 1, COMM1, the lowest port number, an icon for a terminal console, or the only serial port (on a single-port system). This pathname always maps to 2, COMM2, the next numbered port, or (if one serial port is labeled with an icon for a terminal console) the remaining serial port. If your system hardware has been extended to include additional serial ports, the pathnames /dev/tty02, /dev/tty03, and so forth, may also be available to you. However, most systems have only /dev/tty00 and /dev/tty01 as the device pathnames for serial ports. The one parallel port on an AlphaStation or AlphaServer may be labeled with the word printer or a printer icon. On some systems, the paral- lel port may not be labeled. The device pathname for the parallel port is /dev/lp0. Currently, Tru64 UNIX does not fully support parallel printers, so fewer devices are connected to this port as compared to serial ports. If you are connecting a terminal console to your system, it must be connected to the serial port mapped to /dev/tty00. For other serial devices, it does not matter which of the serial ports you choose for the connection. For example, suppose you are setting up a system that has two serial ports, labeled 1 and 2. You intend to use a serial-line terminal rather than a workstation monitor as the system console and also want to connect a serial-line printer to the system. In this case, you must connect the terminal to the port labeled 1 (with the device pathname /dev/tty00). Therefore, you must connect the printer to the remaining port labeled 2 (with the device pathname /dev/tty01). If, for the same type of system, you intend to use a workstation monitor as the system console, it does not matter which serial port you use for a serial-line printer or modem. In other words, you can connect the printer to either port 1 (with pathname /dev/tty00) or port 2 (with pathname /dev/tty01). When prompted to enter a /dev/tty** pathname by the lprsetup script or the Print configuration tool in the CDE Application Manager, you would specify /dev/tty00 if you connected the printer to port 1 or /dev/tty01 if you connected the printer to port 2. See the System Administration manual for more information on setting up consoles (including remote consoles) and printers. See the modem(7) reference page for more information on setting up modems. SEE ALSO
Commands: lprsetup(8) Devices: ace(7), modem(7) System Administration delim off ports(7)

Check Out this Related Man Page

ace(7)							 Miscellaneous Information Manual						    ace(7)

ace - Serial communications interface SYNOPSIS
controller ace0 at * slot ? vector aceintr DESCRIPTION
The ace serial line controller provides a serial communications interface on DEC 2000, AlphaStation, and AlphaServer platforms. The serial communications ports that are controlled by ace adhere to the RS-232 standard and can operate at rates from 50 to 115200 baud (see tty(7)). These communications ports support serial-line printers, modems, and terminals. In alternate console configurations (that is, no graphics head), the terminal to be the system console must be connected to the port that is mapped to /dev/tty00. (See ports(7) for information about mapping AlphaStation and AlphaServer port labels to device pathnames.) Cur- rently, some processors that use the ace driver limit the serial console port to 9600 baud, 8-bit, no parity and no modem support. However, some processor consoles do support baud rates other than 9600 baud and allow the use of modems as console devices. Consult your hardware documentation to determine the type of console support your system provides. The driver for the ace interface supports hardware flow control using the Request to Send (RTS) and Clear to Send (CTS) signals. When hardware flow control is enabled, the flow of input data is controlled by the RTS signal and the flow of output data is controlled by the CTS signal. If the CTS signal is off, the driver suspends output to that line until the CTS lead is reasserted. Likewise the driver turns off the RTS lead to tell the device connected to the line to stop sending data as a result of congestion on the host side. When the condi- tion clears, the driver turns on the RTS lead to tell the device to resume sending data. The DCD (carrier detect) timer value defaults to 2 seconds. This value may be changed if your modem hardware requires a different value. the change can be made in the /etc/sysconfigtab file as follows: ace: dcd_timer=n where n is the time interval in seconds, and can be set to 0 (no timeout), 1, or 2 seconds. Alternatively, you can use the sysconfig com- mand to set the same time interval option as follows: # sysconfig -r ace dcd_timer=[n] If you use the sysconfig command, the value will not be preserved when the system is rebooted. To preserve the setting, put the entry in the /etc/sysconfigtab file NOTES
If you are using the alternate system console to perform kernel debugging, you must change the kdebug entry in the /etc/remote file to use /dev/tty01; when the kernel is running in debugging mode, no other application can use the port. See Kernel Debugging for information on setting up your system for kernel debugging. RESTRICTIONS
Unless alternative specifications are stated in your system hardware documentation, data communications equipment attached to the console serial port in alternate console configurations must be set to 9600 baud, 8-bits, no parity. If a serial console is being used, /dev/tty00 cannot be opened by another process. The ace driver enforces this restriction. Baud rates greater than 38400 are not supported on the two primary serial ports on the DEC 2000 system. However, if you use an ISA serial or modem card that is capable of communicating at the higher rates, the higher rates are supported. FILES
console terminal local terminal local terminal RELATED INFORMATION
MAKEDEV(8), console(7), devio(7), modem(7), ports(7), tty(7) Kernel Debugging System Administration delim off ace(7)

Featured Tech Videos