dosbox -version

The optional file argument should be a DOS executable or a directory. If it is a dos executable (.com .exe .bat) the program will run automatically. If it is a directory, a DOS session will run with the directory mounted as C:\.

For an introduction type INTRO inside dosbox.

-fullscreen

Start dosbox in fullscreen mode.

-startmapper

Start the internal keymapper on startup of dosbox. You can use it to change the keys dosbox uses.

-noautoexec

Skips the [autoexec] section of the loaded configuration file.

-c command

Runs the specified command before running file. Multiple commands can be specified. Each command should start with -c though. A command can be: an Internal Program, a DOS command or an executable on a mounted drive.

-conf configfile

Start dosbox with the options specified in configfile. This file has a section in which you can put commands you wish to execute on startup. Multiple configfiles can be present at the commandline.

-lang langfile

Start dosbox with the language specified in langfile.

-exit

dosbox will close itself when the DOS program specified by fileends.

-machine machinetype

Setup dosbox to emulate a specific type of machine. Valid choices are: hercules, cga, pcjr, tandy, vga(default). The machinetype has influence on both the videocard and the available soundcards.

-version

Output version information and exit. Useful for frontends.

MOUNT [-t type] [-size size] driveletter sourcedirectory [-aspi] [-ioctl] [-usecd number] [-label drivelabel] [-freesize freesize]

MOUNT -cd

MOUNT -u driveletter

Program to mount local directories as drives inside dosbox.

driveletter

The driveletter inside dosbox (eg. C).

sourcedirectory

The local directory you want to have inside dosbox.

-t type

Type of the mounted directory. Supported are: dir (standard), floppy, cdrom.

-size drivesize

Sets the size of the drive. See the examples in the README for details.

-freesize size_in_mb

Sets the amount of free space available on a drive in MB's. This is a more simple version of -size.

-label drivelabel

Sets the name of the drive to drivelabel. Needed on some systems if the cd label isn't read correctly. Useful when a program can't find its cdrom. If you don't specify a label and no lowlevel support is selected (-usecd # and/or -ioctl/aspi):

For win32: label is extracted from "Real Drive".

For Linux: label is set to NO_LABEL.

If you do specify a label this label will be kept as long as the drive

is mounted. It will not be updated !!

-aspi

Forces to use the aspi layer. Only valid if mounting a cdrom under Windows systems with an ASPI-Layer.

-ioctl

Forces to use ioctl commands. Only valid if mounting a cdrom under windows which support them (Win2000/XP/NT).

-usecd number

Forces to use SDL cdrom support for drive number. Number can be found by -cd. Valid on all systems.

-cd

Displays all detected cdrom drives and their numbers. Use with -usecd.

-u

Unmounts a mounted drive. Doesn't work on virtual Drives (like Z:\)

Example:

To mount your /home/dos/dosgames directory as C drive in dosbox:

mount c /home/dos/dosgames

MEM

Display the amount of free memory

CONFIG [-writeconf] [-writelang] file

Write the current configuration or language settings to file, which is located on the local filesystem. Not a mounted drive in dosbox.

The configuration file controls various settings of dosbox: The amount of emulated memory, the emulated soundcards and many more things. It futher allows acces to AUTOEXEC.BAT.

The language file controls all visible ouput of the internal commands and the internal dos. See the section FILES for more information.

LOADFIX [-size] [programname] [parameters]

LOADFIX -f

Program to reduce the amount of memory available. Useful for old programs which don't expect much memory to be free.

[programname]

The name of the program which is executed after loadfix eats up its memory.

[parameters]

Parameters given to the programname executable.

-size

The amount of memory to eat up (in kb). Example -32, -64 or -128

-f

Frees all memory eaten up by loadfix.

RESCAN

Make dosbox reread the directory structure. Useful if you changed something on a mounted drive outside dosbox.(CTRL-F4 does this as well!)

IMGMOUNT

A utility to mount disk images and CD-ROM images in dosbox.

Read the README of dosbox for the full and correct syntax.

BOOT

Boot will start floppy images or hard disk images independent of the operating system emulation offered by dosbox. This will allow you to play booter floppies or boot to other operating systems inside dosbox.

Read the README of dosbox for the full and correct syntax.

IPX

You need to enable IPX networking in the configuration file of dosbox. All of the IPX networking is managed through the internal dosbox program IPXNET. For help on the IPX networking from inside dosbox, type IPXNET HELP and the program will list out the commands and relevant documentation.

Read the README of dosbox for the full and correct syntax.

ALT-ENTER

Go full screen and back.

ALT-PAUSE

Pause emulation.

CTRL-F1

Start the keymapper.

CTRL-ALT-F5

Start/Stop creating a movie of the screen.

CTRL-F4

Swap mounted disk-image (Only used with imgmount). Update directory cache for all drives!

CTRL-F5

Save a screenshot.(png)

CTRL-F6

Start/Stop recording sound output to a wave file.

CTRL-ALT-F7

Start/Stop recording of OPL commands.

CTRL-ALT-F8

Start/Stop the recording of raw MIDI commands.

CTRL-F7

Decrease frameskip.

CTRL-F8

Increase frameskip.

CTRL-F9

Kill dosbox.

CTRL-F10

Capture/Release the mouse.

CTRL-F11

Slow down emulation (Increase dosbox Cycles).

CTRL-F12

Speed up emulation (Decrease dosbox Cycles).

ALT-F12

Unlock speed (turbo button).

These are the default keybindings. They can be changed in the keymapper.

Saved/recorded files can be found in current_directory/capture (can be changed in the configfile). The directory has to exist prior to starting dosbox else nothing gets saved/recorded !

Note: Once you increase your dosbox cycles beyond your computer's maximum capacity, it will produce the same effect as slowing down the emulation. This maximum will vary from computer to computer, there is no standard.

So:

Close every program but dosbox.

Overclock dosbox until 100% of your CPU is used.(CTRL-F12)

Since VGA emulation is the most demanding part of dosbox in terms of actual CPU usage, we'll start here. Increase the number of frames skipped (in increments of one) by pressing CTRL-F8. Your CPU usage should decrease. Go back one step and repeat this until the game runs fast enough for you. Please note that this is a trade off: you lose in fluidity of video what you gain in speed.