FONT20 driver for ET4000

put into autoexec.bat
SET F20=XY

where X and Y select the colock rate

value  clock    result in 80*25 text
                without F20                with F20
   0   25 MHz    62 Hz                      52 Hz
   1   28 MHz    70 Hz (BIOS default)       58 Hz
   2   36 MHz    89 Hz                      74 Hz
   3   40 MHz    99 Hz                      82 Hz
   6   62 MHz   111 Hz                      92 Hz (F20_ET40 default)
   7   44 MHz   161 Hz                     133 Hz

x is the new value for 80*25
y is the new value for other screen resolutions (800*600 graphic,..)

for my monitor i use 'SET F20=66'
 (92 Hz in 80*25 text mode and 69.5 Hz for 800*600 OS/2 Presentation Manager)
 