DOSBoxWiki - User contributions [en]

Other compilers

2008-06-26T21:17:45Z

130.161.82.192:

Free software relies heavily on the GNU Compiler Collection, '''GCC'''. GCC is a reliable and standards compiler and is free software too. However, it does not always generate the best code. Dosbox users might want to try different compilers.

== Pathscale ==

The Pathscale compiler (http://www.pathscale.com) is a compiler that comes under GPL license. While technically free software, it is not free of charge. It has very advanced loop vectorizers to make use of SSE instructions, and makes good use of prefetch instructions to improve effective memory bandwidth. It allows great speed gains on the video and audio processing parts of Dosbox.

Compiling dosbox with maximum optimizations (-Ofast) does not work, it results in an error during linking. The cause of this is the interprocedural analysis option (-ipa), which is activated with -Ofast. Therefore we manually enable all optimizations activated by -Ofast, except -ipa. This is: -O3 -OPT:Ofast -fno-math-errno -ffast-math

This, to compile Dosbox using Pathscale, you can use:

./configure CC=pathcc CXX=pathCC CFLAGS="-O3 -OPT:Ofast -fno-math-errno -ffast-math" CXXFLAGS="-O3 -OPT:Ofast -fno-math-errno -ffast-math"
make
make install

When the above has finished, you can enjoy a nice performance improvement in Dosbox.

Other compilers

2008-06-26T21:08:15Z

130.161.82.192:

Free software relies heavily on the GNU Compiler Collection, '''GCC'''. GCC is a reliable and standards compiler and is free software too. However, it does not always generate the best code. Dosbox users might want to use different compilers.

== Pathscale ==

The Pathscale compiler (http://www.pathscale.com) is a compiler that comes under GPL license. While technically free software, it is not free of charge. It has very advanced loop vectorizers to make use of SSE instructions, and makes good use of prefetch instructions to improve effective memory bandwidth. It allows great speed gains on the video and audio processing parts of Dosbox.

Compiling dosbox with maximum optimizations (-Ofast) does not work, it results in an error during linker. The cause of this is the interprocedural analysis option (-ipa), which is activated with -Ofast. Therefore we manually enable all optimizations activated by -Ofast, except -ipa. This is: -O3 -OPT:Ofast -fno-math-errno -ffast-math

This, to compile Dosbox using Pathscale, you can use:

./configure CC=pathcc CXX=pathCC CFLAGS="-O3 -OPT:Ofast -fno-math-errno -ffast-math" CXXFLAGS="-O3 -OPT:Ofast -fno-math-errno -ffast-math"
make
make install

When the above has finished, you can enjoy a nice performance improvement in Dosbox.

Other compilers

2008-06-26T21:07:54Z

130.161.82.192:

Free software relies heavily on the GNU Compiler Collection,'''GCC'''. GCC is a reliable and standards compiler and is free software too. However, it does not always generate the best code. Dosbox user might want to use different compilers.

== Pathscale ==

The Pathscale compiler (http://www.pathscale.com) is a compiler that comes under GPL license. While technically free software, it is not free of charge. It has very advanced loop vectorizers to make use of SSE instructions, and makes good use of prefetch instructions to improve effective memory bandwidth. It allows great speed gains on the video and audio processing parts of Dosbox.

Compiling dosbox with maximum optimizations (-Ofast) does not work, it results in an error during linker. The cause of this is the interprocedural analysis option (-ipa), which is activated with -Ofast. Therefore we manually enable all optimizations activated by -Ofast, except -ipa. This is: -O3 -OPT:Ofast -fno-math-errno -ffast-math

This, to compile Dosbox using Pathscale, you can use:

./configure CC=pathcc CXX=pathCC CFLAGS="-O3 -OPT:Ofast -fno-math-errno -ffast-math" CXXFLAGS="-O3 -OPT:Ofast -fno-math-errno -ffast-math"
make
make install

When the above has finished, you can enjoy a nice performance improvement in Dosbox.

Other compilers

2008-06-26T21:07:18Z

130.161.82.192: New

'''GCC''' is a reliable and standards compiler and is free software too. However, it does not always generate the best code. Dosbox user might want to use different compilers.

== Pathscale ==

The Pathscale compiler (http://www.pathscale.com) is a compiler that comes under GPL license. While technically free software, it is not free of charge. It has very advanced loop vectorizers to make use of SSE instructions, and makes good use of prefetch instructions to improve effective memory bandwidth. It allows great speed gains on the video and audio processing parts of Dosbox.

Compiling dosbox with maximum optimizations (-Ofast) does not work, it results in an error during linker. The cause of this is the interprocedural analysis option (-ipa), which is activated with -Ofast. Therefore we manually enable all optimizations activated by -Ofast, except -ipa. This is: -O3 -OPT:Ofast -fno-math-errno -ffast-math

This, to compile Dosbox using Pathscale, you can use:

./configure CC=pathcc CXX=pathCC CFLAGS="-O3 -OPT:Ofast -fno-math-errno -ffast-math" CXXFLAGS="-O3 -OPT:Ofast -fno-math-errno -ffast-math"
make
make install

When the above has finished, you can enjoy a nice performance improvement in Dosbox.

DOSBox FAQ

2008-06-26T20:55:02Z

130.161.82.192: Add link to new article about compiling Dosbox with Pathscale

= Performance =

Q. My game runs fine at first then an error message pops up on dosbox saying that the video file format is wrong. How or what can I do to fix this, if there is anything known?

'''Q.''' My game/application runs slowly, how do I improve speed?

'''A.''' Increase cycles. Use core=dynamic. Try different output modes (e.g. output=overlay). Increase Frameskip. Disable unneeded components in the [[dosbox.conf]] such as [[Sound]], mouse or joystick emulation. A nice speedup can be achieved by using a [[Other compilers|different compiler]] than GCC. If all else fails, find a faster computer to run DOSBox on.

Also be sure to check the compatibility section of this FAQ as some game/applications are more trouble (or resource hogs) than others.

'''Q.''' The Sound/Music for my DOS game/application sounds terrible what can I do?

'''A.''' This is a complicated issue covered in the [[Sound]] section of the wiki. It's important to remember to install or setup game/applications correctly to use the correct sound devices (<tt>INSTALL.EXE</tt>, <tt>SOUNDSET.EXE</tt> and <tt>SETUP.EXE</tt> are popular program names to look for). The capabilities of the hardware as well as the preferences of the programmer vary: Therefore what may sound "best" on one particular game may not be the "best" for another. Sometimes changes need to be made to the [[dosbox.conf]] file (or a new conf file) to get the best results.

Also, game sound/music may have an impact on the speed at which the game/application runs and running DOSBox with limited resources may result in incomplete or 'choppy' sound being heard. (see previous question)

Q. How do I change the memory size so that I can run programs that require more than the default settings (eg. Windows 1.01 or some other demanding OS)?

= Usage =
'''Q.''' My backslash key is mapped to ']' with DOSBox in Vista. Is there a workaround?

'''A.''' Press <tt>CTRL-F1</tt> to enter the [[keymapper]] and select the backslash with your mouse. Press the <tt>DELETE</tt> button that will show up on your screen. Then press <tt>ADD</tt> to bind backslash to another key. Simply press an unused key to bind it to this. Press <tt>SAVE</tt> and then <tt>EXIT</tt> to return to the main screen.

'''Q.''' My cursor is trapped within the DOSBox window when I click inside. How do I get the cursor out?

'''A.''' DOSBox will capture your mouse when you click inside the display window (and you have '''<tt>autolock=true</tt>''' set in the [[Dosbox.conf]]). Simply press '''<tt>CTRL-F10</tt>''' to release the mouse.

'''Q.''' I have set Gnome to load DOSBox when I click on .COM files. How do I script it to exit DOSBox when I quit from the game?

'''A.''' with -exit as commandline parameter for DOSBox.

'''Q.''' How do I access my hard drive/cdrom in DOSBox?

'''A.''' See the information on the [[MOUNT]] command, or type <tt>intro mount</tt> or <tt>intro cdrom</tt> in DOSBox for the basics.

'''Q.''' I have an ISO image I made of files for backup purposes. How do I access it in DOSBox?

'''A.''' See the information on the [[IMGMOUNT]] command

'''Q.''' How do I unmount or change images? I need to swap CD images in the drive.

'''A.''' You don't "unmount", you may assign more than one image file to [[IMGMOUNT]], to swap images use <tt>CTRL-F4</tt>.

'''Q.''' I have created an image from a CD that includes CD audio tracks, when I access it in DOSBox only the first (data) track is available.

'''A.''' Be sure to use the bin/cue format for mixed mode CDs (CDs with a data and audio tracks) and always pass the cue file to [[IMGMOUNT]].

'''Q.''' I can't find the ":" symbol anywhere in my dosbox. I am using ista on a laptop. Please advice me how to fix the problem.