## AdvanceMAME FAQ

This is a collection of Frequently Asked Questions.

The sections of this document are:

| 1 General FAQ
|  | 1.1 What version is this FAQ ?
|  | 1.2 Where can I get the latest version of this FAQ ?
|  | 1.3 What is MAME ?
|  | 1.4 How is AdvanceMAME different from MAME ?
|  | 1.5 I have a question that is not answered in this FAQ. Where can I get help ?
| 2 AdvanceMAME FAQ
|  | 2.1 Is the Linux version of AdvanceMAME able to program my video board ?
|  | 2.2 Is the DOS version of AdvanceMAME able to program my video board ?
|  | 2.3 Is the Windows version of AdvanceMAME able to program my video board ?
|  | 2.4 How do I automatically record video and audio clips ?
|  | 2.5 When I start a game with AdvanceMAME I see a copyright message before the game starts. How do I get rid of it ?
|  | 2.6 Where can I get ROM-files of games for AdvanceMAME ?
| 3 AdvanceMENU FAQ
|  | 3.1 Why does the mouse and the joystick not work ?
|  | 3.2 Each time I start AdvanceMENU, I see a message about
|  | 3.3 Can I use AdvanceMENU to list my MP3 and MNG collection ?
|  | 3.4 Can I change the colors of AdvanceMENU (eg. to avoid burn-in on arcade monitors) ?
|  | 3.5 How do I configure AdvanceMENU to use a certain video-mode (for use on my arcade monitor) ?
|  | 3.6 How do I avoid AdvanceMENU jumping to different games when I press letter keys ?
| 4 DOS FAQ
|  | 4.1 How can I solve the compiler error "Argument list too long (E2BIG)" and "Error -1" ?
|  | 4.2 What's the best configuration in PURE DOS ?
|  | 4.3 Why can I use only 32M of RAM ? I have more RAM.
|  | 4.4 Why can I use only 64M of RAM ? I have more RAM.
|  | 4.5 Which is the minimum memory requirement ?
|  | 4.6 Which is the maximum memory required ?
|  | 4.7 How can I use two mice (or a trackball and a spinner) ?
| 5 Linux FAQ
|  | 5.1 Is there a way I can test the Linux version of AdvanceMAME without installing Linux on my system ?
|  | 5.2 How can I load the svgalib_helper.o kernel module automatically ?
|  | 5.3 On scrolling games I see a missing frame every 5 or 10 seconds, also with vsync enabled. How can I fix it ?
|  | 5.4 Using the last svgalib and enabling vsync my system freezes randomly from time to time.
|  | 5.5 How can I enable the XFree86 DGA extension ?
|  | 5.6 I have some background system activity, and the emulated games are not playing smoothly. How do I fix this ?
|  | 5.7 Can I run AdvanceMENU directly from /etc/inittab ?
|  | 5.8 Can I run the Advance programs from a readonly filesystem ?
| 6 Windows FAQ
|  | 6.1 The SVGAWIN driver doesn't seem to work with my video board. How can I solve this ?
|  | 6.2 How do I disable the Windows hotkeys ?
| 7 Video FAQ
|  | 7.1 How can I enable the TV-OUT signal (S-VIDEO) of the video board ?
|  | 7.2 Can I connect my Arcade Monitor to the video board and use it with AdvanceMENU and AdvanceMAME ?
|  | 7.3 How can I connect my Arcade Monitor to the video board ?
|  | 7.4 How can I avoid damaging my arcade monitor due to the signals sent out during system startup (before AdvanceMENU and AdvanceMAME starts) ?
|  | 7.5 What is the "tearing" effect ?
|  | 7.6 How can I remove the tearing effect ?
|  | 7.7 How can I reduce the tearing effect ?
|  | 7.8 Does the "double/tripler buffer" help to reduce the tearing effect ?
|  | 7.9 Can I get a good animation with a video mode with arbitrary frequency ?
|  | 7.10 Why are the smaller video modes like 256x224 not working ?
| 8 License FAQ
|  | 8.1 Is MAME Open Source ?
|  | 8.2 Is MAME Free Software ?
|  | 8.3 Is AdvanceMAME Open Source and Free Software ?
|  | 8.4 Which is the license of the AdvanceMAME source ?
|  | 8.5 Why the AdvanceMAME license is called GPL if it's different than the GPL ?
|  | 8.6 Does the MAME license allow linking the MAME source with a GPL source ?
|  | 8.7 Does the GPL license allow to link a GPL source with a MAME source ?
|  | 8.8 Does the GPL license + exception allow linking a GPL + exception source with a MAME source ?
|  | 8.9 The license exception say "MAME library". Is MAME a library or a program ?
|  | 8.10 The GPL FAQ say: "Combining two modules means connecting them together so that they form a single larger program. If either part is covered by the GPL, the whole combination must also be released under the GPL--if you can't, or won't, do that, you may not combine them.". Is it true ?
|  | 8.11 What license is the AdvanceMAME binary under ?
|  | 8.12 Can I sell the AdvanceMAME binary ?
|  | 8.13 Why has SourceForge accepted the AdvanceMAME project and not the xmame project ?
|  | 8.14 Who is the copyright holder of AdvanceMAME ?
| 9 GPL FAQ
|  | 9.1 I am writing free software that uses non-free libraries. What legal issues come up if I use the GPL?
|  | 9.2 Is the developer of a GPL-covered program bound by the GPL? Could the developer's actions ever be a violation of the GPL?
|  | 9.3 I want to distribute binaries, but distributing complete source is inconvenient. Is it ok if I give users the diffs from the "standard" version along with the binaries?
| 10 Copyright

## 1 General FAQ

### 1.1 What version is this FAQ ?

Since the FAQ is part of the AdvanceMAME documentation and included with every version of AdvanceMAME, there has been no need to have a separate version number. The version of the FAQ is therefore equal to the version of AdvanceMAME that it was shipped with.

### 1.2 Where can I get the latest version of this FAQ ?

The latest version of the FAQ is included with the latest version of AdvanceMAME, available for download from the project homepage http://advancemame.sourceforge.net/.

The latest version of the FAQ is also available online at http://advancemame.sourceforge.net/doc-faq.html.

### 1.3 What is MAME ?

MAME means Multiple Arcade Machine Emulator and is a huge effort to create an emulator capable of running a lot of old arcade games. The MAME homepage is at http://www.mame.net/.

### 1.4 How is AdvanceMAME different from MAME ?

AdvanceMAME is a port of MAME, written mainly by Andrea Mazzoleni, with contributions from various other people. The video support in AdvanceMAME is made especially to be able to program the video hardware (graphics adapter) to achieve a more faithful video emulation, also allowing the use with arcade monitors and TVs.

It also contains software filters to improve the image when used on monitors with a higher resolution, such as PC monitors.

### 1.5 I have a question that is not answered in this FAQ. Where can I get help ?

If you have looked through the documentation and still haven't found an answer to your question, you could try posting it to the AdvanceMAME mailing list. Before you post, however, you should check the mailing list archives to make sure your question has not already been answered there. Subscription to the mailing list and archives can be found at http://lists.sourceforge.net/lists/listinfo/advancemame-users.

Also, if possible, check your problem against the official MAME before posting to the AdvanceMAME mailing list.

## 2 AdvanceMAME FAQ

### 2.1 Is the Linux version of AdvanceMAME able to program my video board ?

The Linux version of AdvanceMAME uses both the SVGALIB library and FrameBuffer kernel service to directly program the video board.

The file cardlinx.txt in the documentation directory contains a list of supported graphics adaptors under Linux.

### 2.2 Is the DOS version of AdvanceMAME able to program my video board ?

The DOS version of AdvanceMAME uses a modified version of the Linux SVGALIB library that allows the direct programming the video board.

The file carddos.txt in the documentation directory contains a list of supported graphics adaptors under DOS.

### 2.3 Is the Windows version of AdvanceMAME able to program my video board ?

Under Windows NT/2000/XP AdvanceMAME uses a modified version of the Linux SVGALIB library, called SVGAWIN, that allows the direct programming of the video board.

The file cardwin.txt in the documentation directory contains a list of supported graphics adaptors under Linux.

Under Windows 98/Me you can use the DOS version to directly program your video board.

### 2.4 How do I automatically record video and audio clips ?

Add this script to your advmame.rc. For any game started a 15 seconds clip is recorded.

    script_emulation delay(5000); \
        simulate_event(ui_snapshot, 50); \
        simulate_event(ui_record_start, 50); \
        delay(15100); \
        simulate_event(ui_record_stop, 50); \
        delay(100); \
        simulate_event(ui_cancel, 50);

### 2.5 When I start a game with AdvanceMAME I see a copyright message before the game starts. How do I get rid of it ?

Take a look at the `misc_quiet' option.

### 2.6 Where can I get ROM-files of games for AdvanceMAME ?

Well, not here in any case. And please do not ask for this on the AdvanceMAME mailing list. Such requests are frowned upon on the list, and will only make you look bad to the AdvanceMAME community.

Also note that MAME and hence AdvanceMAME explicitly forbid the distribution of ROM files along with the emulator, and also strictly forbids the use of the emulators for any kind economic gain, either by selling, or by creating systems where games are paid for with coin mechanisms or bill acceptors.

## 3 AdvanceMENU FAQ

### 3.1 Why does the mouse and the joystick not work ?

As default, the mouse and joystick inputs are disabled. To enable them you can use the `device_mouse auto' and `device_joystick auto' options.

### 3.2 Each time I start AdvanceMENU, I see a message about "Updating the ... information file ..." How do I get rid of it ?

The information file is recreated if the emulator executable is newer than the named file. If this happens all the time, you probably have a wrong time setting on your system.

### 3.3 Can I use AdvanceMENU to list my MP3 and MNG collection ?

Yes. You can create a fake emulator to play all your music and video clips. Add the following options in your advmenu.rc :

    emulator "mng" generic ""
    emulator_altss "mng" "C:\CLIP"
    emulator_roms "mng" "C:\CLIP"
    emulator_roms_filter "mng" "*.mng"

    emulator "mp3" generic ""
    emulator_altss "mp3" "C:\MP3;C:\MUSIC"
    emulator_roms "mp3" "C:\MP3;C:\MUSIC"
    emulator_roms_filter "mp3" "*.mp3"

### 3.4 Can I change the colors of AdvanceMENU (eg. to avoid burn-in on arcade monitors) ?

Yes. All the colors of AdvanceMENU can be changed. Take a look at the description of the `ui_color' option in the advmenu documentation.

### 3.5 How do I configure AdvanceMENU to use a certain video-mode (for use on my arcade monitor) ?

Simply copy the modeline (from advmame.rc) into advmenu.rc and specify the width of the video-mode in the `display_size' option.

### 3.6 How do I avoid AdvanceMENU jumping to different games when I press letter keys ?

Use `event_alpha no' in the AdvanceMENU configuration file. This is most often used if you have a control panel wired to a keyboard hack or keyboard controller.

## 4 DOS FAQ

### 4.1 How can I solve the compiler error "Argument list too long (E2BIG)" and "Error -1" ?

If compiling you get the "Argument list too long" error, or "Error -1" you need to use the DJGPP stubedit utility to increase bufsize value for some DJGPP tools, with the following commands:

    stubedit c:\djgpp\bin\gcc.exe bufsize=32k
    stubedit c:\djgpp\bin\ld.exe bufsize=32k
    stubedit c:\djgpp\bin\make.exe bufsize=32k
    stubedit c:\djgpp\lib\gcc-lib\djgpp\3.23\collect2.exe bufsize=32k

You may need to use different paths to the files, especially for collect2.exe.

### 4.2 What's the best configuration in PURE DOS ?

My favorite choice is to use HIMEM, EMM386 and a little cache with SMARTDRV.

In CONFIG.SYS:

    dos=high
    device=C:\DOS\W98\HIMEM.SYS
    device=C:\DOS\EMM386.EXE NOEMS NOVCPI

In AUTOEXEC.BAT:

    smartdrv 1024

If you have a lot of RAM you can use a bigger disk cache like :

    smartdrv 8192

### 4.3 Why can I use only 32M of RAM ? I have more RAM.

Start the EMM386.EXE device in your CONFIG.SYS with the "NOEMS NOVCPI" arguments.

### 4.4 Why can I use only 64M of RAM ? I have more RAM.

Don't use the DOS 6.22 version of the HIMEM.SYS device. Use a newer version, the Windows 98 version works good. You don't need to upgrade your DOS, simply copy the newer HIMEM.SYS from a Windows 98 installation.

### 4.5 Which is the minimum memory requirement ?

With 64 MB of memory you are able to play all the games. At least in PURE DOS with CWSDPMI 5 and with 512 MB of virtual memory.

### 4.6 Which is the maximum memory required ?

With 128 MB you should be able to play all the games without any big speed loss. For the bigger games you may need 512 MB of virtual memory.

### 4.7 How can I use two mice (or a trackball and a spinner) ?

To get support for a second mouse you need the mouse driver in the contrib/optimous directory. This directory also contains a short text instruction file.

## 5 Linux FAQ

### 5.1 Is there a way I can test the Linux version of AdvanceMAME without installing Linux on my system ?

Yes. You can try the AdvanceCD-package, which is a CDROM-image of a small Linux-system configured to run AdvanceMENU and AdvanceMAME on startup. AdvanceCD will autodetect most hardware, but is mainly made for use with PC monitors.

### 5.2 How can I load the svgalib_helper.o kernel module automatically ?

Insert this line :

    alias char-major-209 svgalib_helper

in your /etc/modules.conf file and run the following command once :

    depmod -a

After that the module is loaded automatically every time is needed.

### 5.3 On scrolling games I see a missing frame every 5 or 10 seconds, also with vsync enabled. How can I fix it ?

If you are using a gameport joystick try disabling the joystick support with the `device_joystick none' option.

Or upgrade the svgalib library to version 1.9.16, which supports vsync IRQ for some more graphics adapters.

### 5.4 Using the last svgalib and enabling vsync my system freezes randomly from time to time.

Try using the svgalib patch in the contrib/svgalib directory or downgrade the version to 1.9.15 or 1.9.14.

### 5.5 How can I enable the XFree86 DGA extension ?

Ensure that in your XF86Config file the line :

    Option    "omit xfree86-dga"

is not present or commented. To test it you can use the `dga' utility. Run :

    man dga

### 5.6 I have some background system activity, and the emulated games are not playing smoothly. How do I fix this ?

To run AdvanceMAME the system must be almost in idle state.

Anyway, to reduce "jumpy" effect you can disable the vertical vsync. The problem with vsync is that if the system is busy on a vsync the result is a complete frame drop (a wait of 17 ms).

### 5.7 Can I run AdvanceMENU directly from /etc/inittab ?

The SVGALIB library needs a controlling tty and programs using it cannot be run directly from init. You can anyway start them in a shell, like :

    ::respawn:-/bin/sh -c advmenu

or write a simple program wrapper which sets a tty and execs the program you want, like :

    i=open("/dev/tty1", O_RDWR);
    ioctl(i, TIOCSCTTY, 1);
    exec(...)

### 5.8 Can I run the Advance programs from a readonly filesystem ?

Yes. All the writable files are put in the $HOME/.advance directory. If they are readonly, they are not updated.

## 6 Windows FAQ

### 6.1 The SVGAWIN driver doesn't seem to work with my video board. How can I solve this ?

The SVGAWIN driver is experimental. At present it's only tested on Windows 2000 with a GeForce 2 board. It may not work will all the other boards.

The svgawin drivers are inherently unsafe because they should coexist with the normal Windows drivers.

The most common problem is that the Windows driver sets the video card in a state that the SVGAWIN driver cannot understand or restore.

The only possible solution is to try to reduce the video hardware acceleration to a minimum in DisplayProperties/Settings/Advanced/Troubleshooting.

If you want a stable solution you must use the Linux or DOS version of AdvanceMAME and AdvanceMENU.

Alternatively you can try to use two different video boards, one for Windows and the other for the game display. Check the `device_svgawin_skipboard' option to control which video board to use.

### 6.2 How do I disable the Windows hotkeys ?

Check the Microsoft online documents "Disabling the Windows Key on Microsoft Natural Keyboard" at http://support.microsoft.com/?kbid=181348.

## 7 Video FAQ

### 7.1 How can I enable the TV-OUT signal (S-VIDEO) of the video board ?

You cannot. If the TV-OUT signal is not enabled automatically by your video board you cannot enable it manually.

If you have a TV with SCART input (all european TVs) you can buy or build a VGA to SCART cable.

### 7.2 Can I connect my Arcade Monitor to the video board and use it with AdvanceMENU and AdvanceMAME ?

Yes, this is one of the primary goals of the AdvanceMAME video output layer. But remember that arcade monitors can only accept a certain range of signals (in terms of horizontal and vertical refresh etc.), so make sure you configure these settings correctly in AdvanceMENU and AdvanceMAME before you connect it to your monitor.

### 7.3 How can I connect my Arcade Monitor to the video board ?

If you do not want to use one of the available adaptors that ensure the signal is within specifications, to avoid damaging your monitor, you can simply connect the monitor directly to the graphics card. If your monitor only has one sync-line (so-called composite sync) you will need to convert the separate sync signals of the video board to composite sync. This can be achieved by a circuit such as http://www.tkk.fi/Misc/Electronics/circuits/vga2rgbs_ttl.gif

Some video boards can be configured to generate the composite sync signal. An example is Matrox cards under Linux. Look at the matroxfb-documentation in the kernel sources, and maybe the matroxset-utility.

### 7.4 How can I avoid damaging my arcade monitor due to the signals sent out during system startup (before AdvanceMENU and AdvanceMAME starts) ?

There exists separate hardware adaptors that can be used for this purpose, such as the J-PAC http://www.ultimarc.com/jpac.html

Other options include waiting until AdvanceMENU has started up, before connecting the monitor. This can be achieved either manually, or by hardware controlled by the parallel port (as described in various places).

If your system is running DOS, you can use the "vga" and "video" utilities of the AdvanceCAB package to set the graphics card in an acceptable mode while the system is booting. Note that the POST (Power On Self Test) screen of the BIOS will still be in the "bad" video-mode, so the problem is not solved entirely by these utilities, but they allow for a nice bootup-screen to be displayed.

With some graphics adapters (eg. Matrox), a similar effect can be achieved under Linux by configuring the video mode of the kernel framebuffer.

### 7.5 What is the "tearing" effect ?

The tearing effect is a defect of the animation caused by a wrong synchronization with the game refresh rate and the video mode refresh rate. It generally appears as a horizontal image split line, on the top of this line you see the previous game frame, on the bottom of this line you see the next game frame.

If the game and the video refresh rate are only a little different the tearing split line is slowly moving up or down. If the refreshes are very different the split line is moving randomly.

The tearing effect is mostly noticeable in games with a continuously scrolling background.

### 7.6 How can I remove the tearing effect ?

The only way to remove the tearing effect is to enable the `display_vsync' option. To correctly work this option need a video mode with a refresh rate which is a multiplier of the original game refresh rate. For example for a 50 Hz game you can use video modes of 50, 100, 150 Hz.

### 7.7 How can I reduce the tearing effect ?

If for some reason you cannot use the `display_vsync' option the only way to reduce the tearing effect is to choose a video mode refresh rate which ensure to have a randomly and fast moving tearing split line.

Generally they are high refresh rates, prime with the original game frequency.

### 7.8 Does the "double/tripler buffer" help to reduce the tearing effect ?

No. A generic asynchronous buffer doesn't remove or reduce the tearing effect. A synchronous buffer instead it's exactly like the vsync. AdvanceMAME supports only the asynchronous buffers.

### 7.9 Can I get a good animation with a video mode with arbitrary frequency ?

There is no way to get a perfect animation without using a video mode with the same game refresh rate. You will get the tearing effect or a not smooth animation from some frames skipped or displayed too long.

For example, suppose to use a 70 Hz video mode with a 60 Hz game. You can display every frame for 1/60 of second and get the tearing effect. Alternatively you can display every frame for 1/70 of second, but after 7 frame you need to display a frame for 2/70 of second to synchronize with the original game speed.

The only exception is for frequencies which are multiplier of the original game refresh rate.

### 7.10 Why are the smaller video modes like 256x224 not working ?

Your video board probably isn't able to generate the very low pixelclocks needed. You can try to increase the minimum value of the `device_video_pclock' option. The video mode generation will automatically generate video modes with double or triple horizontal resolutions to force the use of a pixelclock in the specified range.

## 8 License FAQ

### 8.1 Is MAME Open Source ?

No. The MAME License is not an Open Source License as defined at http://www.opensource.org/.

### 8.2 Is MAME Free Software ?

No. The MAME License is not a Free Software License as defined at http://www.gnu.org/.

### 8.3 Is AdvanceMAME Open Source and Free Software ?

Yes. AdvanceMAME is released with the GPL License which is an Open Source and a Free Software License.

### 8.4 Which is the license of the AdvanceMAME source ?

The AdvanceMAME project is released under the GPL license.

In addition you have some extra rights granted by a special license exception which allow you to link the AdvanceMAME GPL source with the not GPL MAME source.

The exception also gives you the rights to eliminate it if you don't like it or if you want to include the AdvanceMAME source in another GPL program. So, AdvanceMAME is 100% GPL.

You can more easily think at it as a sort of double license. A GPL or a GPL + exception. You have all the rights of the GPL, and, if you want, some others.

The only limitation is for AdvanceMAME. AdvanceMAME cannot include external GPL source without the explicit permission of the source copyright holder.

### 8.5 Why the AdvanceMAME license is called GPL if it's different than the GPL ?

The GPL license used by AdvanceMAME isn't modified in any way.

The license exception is added outside the GPL license text. It's added at the top of every source files for which the exception has the validity.

How to add this sort of exceptions is specifically covered on the Official GPL FAQ written by the same people which have written the GPL license and which are the copyright holders of the GPL license.

Specifically, in the Official GPL FAQ you can see that in every source files with the license exception you must add the following text :

"This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version."

Which explicitly claims that the program with the license exception is still GPL.

### 8.6 Does the MAME license allow linking the MAME source with a GPL source ?

Yes. The only requirement of the MAME License for the derivative works is the whole source availability. With the GPL you have it. Obviously this assuming that the MAME License isn't changed and it maintains complete validity.

### 8.7 Does the GPL license allow to link a GPL source with a MAME source ?

No. The GPL license requires that the whole program be released with the GPL license or with a GPL compatible license. The MAME License isn't a GPL compatible license.

### 8.8 Does the GPL license + exception allow linking a GPL + exception source with a MAME source ?

Yes. The license exception specifically allows it.

### 8.9 The license exception say "MAME library". Is MAME a library or a program ?

AdvanceMAME uses only the internal MAME core, which is effectively a library. For example MESS is distributed with the MAME core as a DLL (Dynamic Linked Library) and two different frontends as .EXE files.

Anyway, calling a piece of software a program or a library doesn't change its license.

### 8.10 The GPL FAQ say: "Combining two modules means connecting them together so that they form a single larger program. If either part is covered by the GPL, the whole combination must also be released under the GPL--if you can't, or won't, do that, you may not combine them.". Is it true ?

Yes. But the GPL FAQ speak of a generic GPL program without any exception.

The license exception explicitly allows you to combine the GPL program with MAME. These exceptions exist specifically to solve this problem. Essentially, if your GPL program needs to use another module which is not under a GPL license, you (as copyright holder) can grant at the user the rights to link it with the not GPL module.

The GPL was made to protect the interests of the copyright holder. But if the copyright holder wants, he can relax the license adding specific exceptions that extend the rights of the users. So, the users can do things not generally permitted by the standard GPL license.

### 8.11 What license is the AdvanceMAME binary under ?

The AdvanceMAME binary contains source from AdvanceMAME, MAME, Allegro, SEAL, svgalib, zlib and FreeType2. You must follow ALL these licenses when you use the binary. So, you are only allowed to do things with it, if they are permitted by ALL these licenses.

### 8.12 Can I sell the AdvanceMAME binary ?

No. The AdvanceMAME binary contains compiled MAME source and the "MAME License" prohibits selling.

### 8.13 Why has SourceForge accepted the AdvanceMAME project and not the xmame project ?

SourceForge accepts only Open Source licenses.

The source distribution of AdvanceMAME is released with an Open Source license. So, it was accepted.

The xmame is released with the "MAME License". The MAME License isn't an Open Source license as defined on http://www.opensource.org/. So, it was rejected.

### 8.14 Who is the copyright holder of AdvanceMAME ?

Andrea Mazzoleni is the copyright holder of AdvanceMAME.

Some source and documentation files are also under the copyright of Filipe Estima, Ian Patterson, Randy Schnedler, S. Sakamaki, Mikkel Holm Olsen.

## 9 GPL FAQ

This is an extract of the Official GPL FAQ present at :

| http://www.gnu.org/licenses/gpl-faq.html

### 9.1 I am writing free software that uses non-free libraries. What legal issues come up if I use the GPL?

If the libraries that you link with falls within the following exception in the GPL:

    However, as a special exception, the source code distributed need not
    include anything that is normally distributed (in either source or
    binary form) with the major components (compiler, kernel, and so on) of
    the operating system on which the executable runs, unless that
    component itself accompanies the executable.

then you don't have to do anything special to use them. In other words, if the libraries you need come with major parts of a proprietary operating system, the GPL says people can link your program with them.

If you want your program to link against a library not covered by that exception, you need to add your own exception, wholly outside of the GPL. This copyright notice and license notice give permission to link with the program FOO:

    Copyright (C) yyyy

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

    In addition, as a special exception, <name of copyright
    holder> gives permission to link the code of this program with
    the FOO library (or with modified versions of FOO that use the
    same license as FOO), and distribute linked combinations including
    the two.  You must obey the GNU General Public License in all
    respects for all of the code used other than FOO.  If you modify
    this file, you may extend this exception to your version of the
    file, but you are not obligated to do so.  If you do not wish to
    do so, delete this exception statement from your version.

Only the copyright holders for the program can legally authorize this exception. If you wrote the whole program yourself, then assuming your employer or school does not claim the copyright, you are the copyright holder--so you can authorize the exception. But if you want to use parts of other GPL-covered programs by other authors in your code, you cannot authorize the exception for them. You have to get the approval of the copyright holders of those programs.

When other people modify the program, they do not have to make the same exception for their code--it is their choice whether to do so.

Adding this exception eliminates the legal issue, ...

http://www.gnu.org/licenses/gpl-faq.html#WritingFSWithNFLibs

### 9.2 Is the developer of a GPL-covered program bound by the GPL? Could the developer's actions ever be a violation of the GPL?

Strictly speaking, the GPL is a license from the developer for others to use, distribute and change the program. The developer itself is not bound by it, so no matter what the developer does, this is not a "violation" of the GPL.

However, if the developer does something that would violate the GPL if done by someone else, the developer will surely lose moral standing in the community.

http://www.gnu.org/licenses/gpl-faq.html#TOCDeveloperViolate

### 9.3 I want to distribute binaries, but distributing complete source is inconvenient. Is it ok if I give users the diffs from the "standard" version along with the binaries?

This is a well-meaning request, but this method of providing the source doesn't really do the job.

A user that wants the source a year from now may be unable to get the proper version from another site at that time. The standard distribution site may have a newer version, but the same diffs probably won't work with that version.

So you need to provide complete sources, not just diffs, with the binaries.

http://www.gnu.org/licenses/gpl-faq.html#TOCDistributingSourceIsInconvenient

## 10 Copyright

This file is Copyright (C) 2003, 2004, 2005, Andrea Mazzoleni, Mikkel Holm Olsen (http://symlink.dk/)