Appendix D. Random Bits D.1. Linux Devices In Linux various special files can be found under the directory /dev . These files are called device files and behave unlike ordinary files. The most common types of device files are for block devices and character devices. These files are an interface to the actual driver (part of the Linux kernel) which in turn accesses the hardware. Another, less common, type of device file is the named pipe . The most important device files are listed in the tables below. The mouse can be used in both the Linux console (with gpm) and the X window environment. Normally, this is a simple matter of installing gpm and the X server itself. Both should be configured to use /dev/input/mice as the mouse device. The correct mouse protocol is named exps2 in gpm, and ExplorerPS/2 in X. The respective configuration files are /etc/gpm.conf and /etc/X11/xorg.conf . 109 D.1.1. Setting Up Your Mouse fd0 First Floppy Drive fd1 Second Floppy Drive sda First hard disk sdb Second hard disk sda1 First partition of the first hard disk sdb7 Seventh partition of the second hard disk sr0 First CD-ROM sr1 Second CD-ROM ttyS0 Serial port 0, COM1 under MS-DOS ttyS1 Serial port 1, COM2 under MS-DOS psaux PS/2 mouse device gpmdata Pseudo device, repeater data from GPM (mouse) daemon cdrom Symbolic link to the CD-ROM drive mouse Symbolic link to the mouse device file null Anything written to this device will disappear zero One can endlessly read zeros out of this device