Linux PC: The best of both worlds
If you are one of those people who have a Linux PC on their desk, then
this document might be useful for you. It describes how to get the best
of both worlds: UNIX and MS-DOS.
Switching at boot time
When you turn the computer on, it will (after some initializations)
display a menu where you can select Linux or DOS (using the cursor
keys). If no choice is made, Linux is booted by default.
Virtual consoles
Apart from the graphical X window interface, the screen of a Linux PC
can also be used as a "Virtual Console", i.e. a text session. This can
of course be used for any program that doesn't require X, e.g. reading
mail. But it can alson be used to run the DOS emulator, by typing
dos at the UNIX shell prompt.
Switching to and from Virtual Consoles works thus:
Control-Alt-F1 brings you to the first VC, Control-Alt-F2 to the second
and Control-Alt-F3 brings you back to X-windows (unless more than 2 VCs
are installed, but this is our default configuration).
There is now also a set of utilities called open
and switchto to switch to Virtual Consoles.
Note that switching between Virtual Consoles is even possible if
a user has locked X using xlock. This is a nice way to
allow another user to temporarily use your screen without logging out.
Of course, your guest doesn't have X windows, so this is a limited
session, but better than nothing (and possibly better than a
telnet session on a non-linux PC.
DOS emulator
When you only want to run a DOS application without quitting X and rebooting,
you can use the DOS emulator. This can be done in one of three ways:
- dos -
This starts the DOS emulator in your current terminal. Quite limited,
unless this terminal is a "virtual console" (see above).
- xdos -
(also available from the "terminal" menu. This opens a window and
runs the DOS emulator. Most applications work, but graphics are not
available (although all special characters from the IBM character set
are available).
- vcdos -
This switches to a new "virtual console" and starts the emulator.
After you finish the emulator (using EXITEMU),
vcdos will switch back to your original screen.
Switching manually is also possible.
Usually, Control-Alt-F3 switches to X, and Control-Alt-F4 to DOS.
Almost all applications work, except from things that want to take
over the whole machine, such as Windows and some games.
Access to the network is also not possible (the controller of the
network card gets locked by linux and is not available to DOS).
To leave the DOS emulator in any of these cases, type EXITEMU
at the DOS prompt.
NEW: The DOS partition of the harddisk is now available as
C: (as in DOS itself) in stead of D:.
The DOS partition is also permanently mounted under Linux as /dos/c.
WARNING:
DOS is not prepared for multitasking, so be careful
when running multiple DOS sessions. There is nothing preventing you from
damaging files by opening them twice.
Also, DOS has no idea of file ownership, so everyone can access every
file on the DOS partition or floppy disk.
David.Jansen@strw.leidenuniv.nl
Last modified: Mon Nov 11 10:35:56 MET 1996