Parallel port manager (QNX Neutrino)

Note: You must be root to start this driver.


devc-par [-b port] [-N name] [-O size] [-o opt[,opt...]]
         [-P priority] [-p address] [-s number] &

Runs on:

QNX Neutrino




-b port
Which BIOS port to use (1-4). Don't use this option with the -p option.
-N name
Register the parallel devices using name as the name (defaults to par, giving /dev/par).
-O size
Size of the output buffer in bytes (default 1000).
-o opt[,opt...]
Additional options, separated by commas. The options include:
  • nodaemon — don't call procmgr_daemon() to make the driver run in the background. Use this option if you need to know when the device terminates.
  • priority=prio — set the working priority of the internal pulse.
-P priority
Priority of the writer agent task. Because the writer agent polls the parallel ports, it should run at a lower priority than most other tasks. The default priority is 9.
-p address
Base I/O address of the parallel port. The I/O port address may be specified in hexadecimal form (e.g., 0x140) or octal form (e.g., 0140) as well as in decimal. Don't use this option with the -b option.
-s number
Number of times to check a busy printer before resorting to a 100 ms sleep. (Default is -1, always sleep if the printer is busy.)


The devc-par manager is a parallel port manager for the QNX Neutrino RTOS. It can support up to 4 parallel ports.

The devc-par driver polls the hardware to detect if a character has been sent.

If you don't specify any ports (using the -p or -b options), devc-par tries to interrogate the BIOS area to determine the number of parallel ports detected by the BIOS. If no ports are found, devc-par silently exits.

You can use the -p option to override the use of the BIOS data area (at 0040:0008).

The only translation of output is the mapping of a newline character to a CR/LF if the OPOST flag is set.

Reading from devc-par works the same as reading from /dev/null.


Start devc-par, defaulting for all parallel ports found by the BIOS:

devc-par &

Start devc-par with only the first parallel port:

devc-par -p 0x3f8 &


devc-par -b 1 &