Specifications

AMD Geode™ GeodeROM Functional Specification 169
Video BIOS Support
32087C
13.1.8 Function 07h - Scroll Down
Description:
Causes a specified rectangular area of the screen to move down a given number of lines. The remaining rows at the
top of the area are cleared with a given fill attribute. The data outside of this area is unaffected. This function only oper-
ates on the active page.
Setting the number of lines to scroll to a zero (“0”) causes the entire area to be cleared with the fill attribute. In text
mode, this fill attribute is a text attribute (part of the character/attribute pair that define characters in text mode). The
rectangular area is filled with a space character (ASCII 20h) and the fill attribute is used as the attribute in that region.
The standard fill attribute in text modes is a 07h.
In planar graphics mode, the fill attribute is actually the color to fill with. For example a fill attribute of 02h actually fills
the area with a green rectangle. The standard fill attribute for graphics modes is a 00h.
Passed:
Returns:
None.
13.1.9 Function 08h - Read Character and Attribute
Description:
Returns the character and attribute at the current cursor position. In graphics modes, only the character code is
returned and then only if the background data is 0 (black).
Passed:
Returns:
Parameter Description
AH 07h
DS Seg0
AL Number of lines:
0 = Blank entire window
BH Attribute used to blank line
CL Upper left column
CH Upper left row
DL Lower right column
DH Lower right row
Parameter Description
AH 08h
DS Seg0
Parameter Description
AL Character read
AH Attribute read