the MDA, CGA and EGA cards, as well as multiple new modes. Standard graphics modes 640×480 in 16 colors or monochrome 640×350 or 640×200 in 16 colors or monochrome (EGA compatibility) 320×200 in 256 colors (Mode 13h) 320×200 in 4 or 16 colors (CGA compatibility) The 640×480 16-color and 320×200 256-color modes had fully redefinable palettes, with each entry selected from an 18-bit (262,144-color) gamut. The other modes defaulted to standard EGA or CGA compatible palettes and instructions, but still permitted remapping of the palette with VGA-specific commands. 640×480 graphics mode As the VGA began to be cloned in great quantities by manufacturers who added ever-increasing capabilities, its 640×480, 16-color mode became the de facto lowest common denominator of graphics cards. By the mid 1990s, a 640×480×16 graphics mode using the VGA memory and register specifications was expected by operating systems such as Windows 95 and OS/2 Warp 3.0, which provided no support for lower resolutions or bit depths, or support for other memory or register layouts without additional drivers. Well into the 2000s, even after the VESA standard for graphics cards became commonplace, the "VGA" graphics mode remained a compatibility option for PC operating systems. Other graphics modes Nonstandard display modes can be implemented, with horizontal resolutions of: 512 to 800 pixels wide, in 16 colors 256 to 400 pixels wide, in 256 colors And heights of: 200, or 350 to 410 lines (including 400-line) at 70 Hz refresh rate, or 224 to 256, or 448 to 512 lines (including 240 or 480-line) at 60 Hz refresh rate 512 to 600 lines at reduced vertical refresh rates (down to 50 Hz, and including e.g. 528, 544, 552, 560, 576-line), depending on individual monitor compatibility. For example, high resolution modes with square pixels are available at 768×576 or 704×528 in 16 colors, or medium-low resolution at 320×240 with 256 colors. Alternatively, extended resolution is available with "fat" pixels and 256 colors using, e.g. 400×600 (50 Hz) or 360×480 (60 Hz), and "thin" pixels, 16 colors and the 70 Hz refresh rate with e.g. 736×410 mode. "Narrow" modes such as 256×224 tend to preserve the same pixel ratio as in e.g. 320×240 mode unless the monitor is adjusted to stretch the image out to fill the screen, as they are derived simply by masking down the wider mode instead of altering pixel or line timings, but can be useful for reducing