PARPORT_CLAIM_OR_BLO(9) Parallel Port Devices PARPORT_CLAIM_OR_BLO(9)NAME
parport_claim_or_block - claim access to a parallel port device
SYNOPSIS
int parport_claim_or_block(struct pardevice * dev);
ARGUMENTS
dev
pointer to structure representing a device on the port
DESCRIPTION
This behaves like parport_claim, but will block if necessary to wait for the port to be free. A return value of 1 indicates that it slept;
0 means that it succeeded without needing to sleep. A negative error code indicates failure.
COPYRIGHT Kernel Hackers Manual 3.10 June 2014 PARPORT_CLAIM_OR_BLO(9)
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ports(7) Miscellaneous Information Manual ports(7)NAME
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)