# Physical Devices (Windows*)

This topic only applies to Windows* operating systems.

Inout/Output (I/O) statements that do not refer to a specific file or I/O device read from standard input and write to standard output. Standard input is the keyboard, and standard output is the screen (console). To perform input and output on a physical device other than the keyboard or screen, specify the device name as the file name to be read from or written to.

Some physical device names are determined by the host operating system; others are recognized by Intel® Fortran. Extensions on most device names are ignored.

File Names for Device I/O
Device | Description
--- | ---
CON | Console (standard output)
PRN | Printer
COM1 | Serial port #1
COM2 | Serial port #2
COM3 | Serial port #3
COM4 | Serial port #4
LPT1 | Parallel Port #1
LPT2 | Parallel Port #2
LPT3 | Parallel Port #3
LPT4 | Parallel Port #4
NUL | NULL device. Discards all output; contains no input.
AUX | Serial port #1
LINE | Serial port #1
USER | Standard output
ERR | Standard error
CONOUT$ | Standard output
CONIN$ | Standard input

### Note

If you use the LINE, USER, or ERR name with an extension, for example, LINE.TXT, Fortran will write to a file rather than to the device.

Examples of opening physical devices as units are:

      OPEN (UNIT = 4, FILE = 'PRN')
      OPEN (UNIT = 7, FILE = 'LPT2', ERR = 100)

Parent topic: Fortran I/O