MAME, or Multiple Arcade Machine Emulator, is a program for your computer that emulates the inner workings of an arcade machine, allowing you to play a variety of games. In addition, MAME allows you to configure a variety of computer specific features such as vertical sync.
MAME is a free software download available at the developer's website. Currently, MAME allows you to play over 2,000 arcade games ranging from the 1970s to present day. It does this by emulating the hardware specifications of these machines. The official version of MAME is a command line program and must be run from the command prompt. However, to set up various options, such as vertical sync, you must do so from the Mame.ini file located in your "Mame" directory. In addition to setting up vertical sync, you can also change the rendering software used to display the games, the screen size and the resolution of the screen.
Vertical sync, also known as vsync, is found in the options of almost every computer game and MAME is no exception. The technical description of vertical sync, according to Techopedia, is that it "prevents the video card from changing the display memory until the monitor is done with its current refresh cycle." In other words, vertical sync makes sure your graphics card and monitor are always synced together. When turned on, vertical sync eliminates screen tearing, which is jagged lines that appear across your screen during game play, the result of your monitor lagging behind your graphics card. For many players, these lines are not noticeable. However, while turning on vertical sync eliminates these lines, it can also lower your frame rate making a game run slower than normal.
Setting Vertical Sync in MAME
In MAME, you can set your Vertical Sync to either "On" or "Off" in the Mame.ini file, located in your "Mame" directory. If you cannot find this file, you can generate a new one by typing Mame -cc while in the "Mame" directory in a command prompt. The file is generated as a notepad file so not extra programs are necessary to access it. Once the file is open, scroll down to the section titled "Windows Video Options." Located under this is "waitvsync," which is the vertical sync display option. The number next to it determines if vsync is on or off; zero means it is off while one means it is on. If you want to use vertical sync in MAME, change the number to one and save the file. To turn vertical sync back off, change the number back to zero. By default, waitvsync is set to zero.
Setting Vertical Sync Through Graphics Card
It is also possible to force vertical sync through to any program through your graphics card. All Nvidia and AMD cards include programs that allow you to modify how specific parts of the card are used on certain programs, which override any options in that particular program. However, depending on your card and your current drivers, the means to access these programs can be different. Consult your card's documentation for how to force vertical sync onto a program from your graphics card.