 Many gamers had several boot disks with different configurations for different games.In later versions of MS-DOS, "boot menu" scripts allowed various configurations to be selectable via a single "boot disk".In the mid- to later 1990s, while many games were still written for DOS, the 640 KB limit was eventually overcome by putting parts of the game's data and/or program code above the first 1 MB of memory and using the code below 640 KB to access the extended memory (using DOS extension methods), with code being swapped into the lowest 1 MB of RAM as overlays.