PC Video Modes

These notes were written in the late 1980s or early 1990s. I thought they would be fun to keep around.

Many Decades Ago...

In the DOS/Windows world, different graphics cards operate monitors in different “modes”. Here is a summary of modes supported by various video board manufacturers.

All VGA and VGA-compatible boards support the following:

    Mode Resolution Colors T/G  CharBlock   AlphaRes
    ------------------------------------------------
    0,1  360x400    16     T    9x16        40x25
    2,3  720x400    16     T    9x16        80x25
    4,5  320x200    4      G    8x8         40x25
    6    640x200    2      G    8x8         80x25
    7    720x400    mono   T    9x16        80x25
    D    320x200    16     G    8x8         40x25
    E    640x200    16     G    8x8         80x25
    F    640x350    mono   G    8x14        80x25
    10   640x350    16     G    8x14        80x25
    11   640x480    2      G    8x16        80x30
    12   640x480    16     G    8x16        80x30
    13   320x200    256    G    8x8         40x25

Modes in the range hex 14..FF are manufacturer dependent. For example, the Trident TVGA8900CL supports these:

    Mode Resolution Colors T/G  CharBlock   AlphaRes
    ------------------------------------------------
    50   640x480    16     T    8x16        80x30
    51   640x473    16     T    8x11        80x43
    52   640x480    16     T    8x8         80x60
    53   1056x350   16     T    8x14        132x25
    54   1056x480   16     T    8x16        132x30
    55   1056x473   16     T    8x11        132x43
    56   1056x480   16     T    8x8         132x60
    57   1188x350   16     T    9x14        132x25
    58   1188x480   16     T    9x16        132x30
    59   1188x473   16     T    9x11        132x43
    5A   1188x480   16     T    9x8         132x60
    5B   800x600    16     G    8x8         100x75
    5C   640x400    256    G    8x16        80x25
    5D   640x480    256    G    8x16        80x30
    5E   800x600    256    G    8x8         100x75
    5F   1024x768   16     G    8x16        128x48
    60   1024x768   4      G    8x16        128x48
    61   768x1024   16     G    8x16        96x64
    62   1024x768   256    G    8x16        128x48
    6C   640x480    16M    G    8x16        80x30
    75   640x480    64K    G    8x16        80x30
    77   800x600    64K    G    8x8         100x75

The VESA standards define the operation of modes in the range 100 hex and above. The Diamond Viper VLB supports a subset of these, namely:

    Mode Resolution Colors T/G  CharBlock   AlphaRes
    ------------------------------------------------
    100  640x400    256    G    8x16        80x25
    101  640x480    256    G    8x16        80x30
    102  800x600    16     G    8x8         100x75
    103  800x600    256    G    8x8         100x75
    105  1024x768   256    G    8x16        128x48
    107  1280x1024  256    G    8x16        160x64
    109  1188x400   16     T    9x16        132x25
    10A  1188x387   16     T    9x9         132x43
    110  640x480    32K    G    8x16        80x30
    111  640x480    64K    G    8x16        80x30
    112  640x480    16M    G    8x16        80x30
    113  800x600    32K    G    8x8         100x75
    114  800x600    64K    G    8x8         100x75
    115  800x600    16M    G    8x8         100x75
    116  1024x768   32K    G    8x16        128x48
    117  1024x768   64K    G    8x16        128x48
    122  1152x900   256    G    8x16        144x56?
    124  1600x1200  256    G    8x16        200x75

Notes:

  1. 'T' means text-only. In text mode, ASCII values are stored in video memory, rather than pixel values.
  2. 'mono' means drives a monochrome display, not necessarily that only two colors can be displayed at one time. In mode F, there are actually four "colors" - black, white, bright, and blinking.