Working with DOS

DOS devices under the UnixWare system

The UnixWare system sees every piece of equipment attached to the computer as a file; it communicates with devices such as mass storage systems and printers by reading from and writing to special device files stored in /dev. Each device file has a name that corresponds to the physical attributes of the device itself.

The hard disk can be divided into one or more partitions, each of which is accessed in the same way, using a device file. The DOS partition on the hard disk is accessed through /dev/disk1 for the first hard disk, and /dev/disk2 for a second hard disk.

To eliminate the need to remember the various device files, a file exists that lets your system administrator define DOS drive names that you can use in place of UNIX device files. This file is called /etc/default/msdos, and, by default, includes the following entries:

   A=/dev/rdsk/f0t
   B=/dev/rdsk/f1t
   X=/dev/rdsk/f0t
   Y=/dev/rdsk/f1t
   .
   .
   .
   #C=/dev/rdsk/c0b0t0d0p1
   D=/dev/rdsk/c0b0t0d0p1

This means that when you are using the DOS partition, you can use A: and X:, and B:, and Y: instead of the floppy diskette drives /dev/rdsk/f0t and /dev/rdsk/f1t respectively. Similarly, you can use D: instead of the hard disk partition /dev/rdsk/c0b0t0d0p1. If you remove the comment from the line

   #C=/dev/rdsk/c0b0t0d0p1

you can also use C: instead of /dev/rdsk/c0b0t0d0p1.

The string ``p1'' in the hard disk example refers to the first partition created by fdisk(1M) on your hard disk. Use ``p2'' if the DOS partition is the section partition, ``p3'' if it is the third partition, and ``p4'' if it is the fourth partition.