INT 10,6 - Scroll Window Up

AH = 06

AL = number of lines to scroll, previous lines are

blanked, if 0 or AL > screen size, window is blanked

BH = attribute to be used on blank line

CH = row of upper left corner of scroll window

CL = column of upper left corner of scroll window

DH = row of lower right corner of scroll window

DL = column of lower right corner of scroll window

returns nothing

- in video mode 4 (300x200 4 color) on the EGA, MCGA and VGA

this function scrolls page 0 regardless of the current page

- can be used to scroll graphics screens, using character coords

- on CGA's this function disables video adapter, causing flitter