Working with disks, tapes, and CD-ROMs

Identifying device files

The device files in /dev have names that correspond to the characteristics of the devices themselves. The following steps show how to work out the name of the device file to use when specifying a floppy disk drive, for example:

  1. All floppy disk devices are located in /dev and begin with rfd (the ``r'' is short for ``raw'', because the SCO OpenServer system has to access the disk directly). The ``fd'' stands for floppy disk. So start the device filename with /dev/rfd.

  2. If your computer has only one floppy disk drive, follow this with a number ``0''. If your computer has two or more drives, you can follow it with a ``0'', ``1'' or higher number (depending on whether you want to format a disk in the first, second, or subsequent drive).

  3. Follow this digit with the number of tracks per inch on the disk. This is usually indicated on the disk label. The standard number of tracks per inch on different disks are as follows:

    Low-density 5¼ inch disks (360KB)

    Double-density 3½ inch disks (720KB)

    High-density 5¼ inch disks (1.2MB)

    High-density 3½ inch disks (1.44MB)

  4. Follow this number with either ``ds'' if the disk is double-sided, or ``ss'' if it is single-sided.

  5. Finally, finish the device name by adding the number of sectors per track on the disk, as follows:

    Standard 5¼ inch or 3½ inch floppy disk

    High-density 5¼ inch floppy disk

    High-density 3½ inch floppy disk
In this way, a name such as /dev/rfd096ds15 can be constructed to indicate a floppy disk drive. Its name literally means ``raw floppy disk 0; 96 tracks per inch; double-sided; fifteen sectors per track.''

A summary of the most common types of floppy disk is given in the following table:

Device code Size and type of backup media
rfd048ds9 5¼ inch 360KB floppy disk
rfd096ds15 5¼ inch 1.2MB floppy disk
rfd0135ds9 3½ inch 720KB floppy disk
rfd0135ds18 3½ inch 1.44MB floppy disk
Note that all of these entries apply to the first drive (drive 0) on the system. If you want to use the second drive, change the 0 after ``rfd'' to 1; if you want to use the third drive, change the 0 to 2, and so on.

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Previous topic: Using UNIX devices

© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003