Specifications

182 AMD Geodeā„¢ GeodeROM Functional Specification
Video BIOS Support
32087C
13.1.18.10Subfunction 20h: Load Upper 8x8 Graphics Character Set
Sets the INT 1Fh vector to the pointer passed in ES:BP. This font pointer is only used in modes 4, 5 and 6 for the upper
half (character 128-255) of the character set. The font pointer at the INT 1Fh vector is valid until the next mode set or
the next call to this subfunction.
Passed:
Returns:
None.
13.1.18.11Subfunction 21h: Load User Graphics Character Set
Sets the INT 43h vector to the pointer passed in ES:BP. This font pointer is used to draw all characters in graphics
modes, except modes 4, 5, 6, which only use the lower 128 characters of this table. The pointer to the upper half of the
font for modes 4, 5, 6 is located at the INT 1Fh vector. The font pointer at the INT 43h vector is valid until the next mode
set or the next call to load a graphics character set.
Passed:
Returns:
None.
Parameter Description
AH 11h
AL 20h
ES:BP Pointer to font
Parameter Description
AH 11h
AL 21h
BL Row specifier:
0 = User
1 = 14
2 = 25
3 = 43
CX Character height (bytes per character)
DL Rows: Passes the number of rows if BL is set to 0 on entry. Otherwise, BL contains a row specifier.
ES:BP Pointer to font