Table 1. Preset Timing Modes
Display Mode
Horizontal
Frequency
(kHz)
Vertical
Frequency
(Hz)
Pixel Clock
(MHz)
Sync Polarity
(H/V)
IBM, 640 x 350 31.469 70.086 25.175 +/-
IBM, 640 x 480 31.469 59.940 25.175 -/-
IBM, 720 x 400 31.469 70.087 28.322 -/+
MAC, 640 x 480 35.000 66.667 30.240 -/-
MAC, 832 x 624 49.726 74.551 57.284 -/-
VESA, 640 x 480 37.500 75.000 31.500 -/-
VESA, 640 x 480 37.861 72.809 31.500 -/-
VESA, 800 x 600 35.156 56.250 36.000 -/-
VESA, 800 x 600 37.879 60.317 40.000 +/+
VESA, 800 x 600 46.875 75.000 49.500 +/+
VESA, 800 x 600 48.077 72.188 50.000 +/+
VESA, 1024 x 768 48.363 60.004 65.000 -/-
VESA, 1024 x 768 56.476 70.069 75.000 -/-
VESA, 1024 x 768 60.023 75.029 78.750 +/+
Horizontal Frequency
The time to scan one line connecting the right edge to the left edge of the
screen horizontally is called Horizontal Cycle and the inverse number of the
Horizontal Cycle is called Horizontal Frequency. Unit: kHz
Vertical Frequency
Like a fluorescent lamp, the screen has to repeat the same image many
times per second to display an image to the user. The frequency of this
repetition is called Vertical Frequency or Refresh Rate. Unit: Hz