Specifications

AMD Geode™ GeodeROM Functional Specification 197
Video BIOS Support
32087C
13.2.6.2 Subfunction 01h: Get Bank
Passed:
Returns:
13.2.7 Function 06h: VBE Set/Get Logical Scan Line Length
The subfunctions either set or get the logical scan line length (sometimes referred to as “row offset”). The logical scan line
length can be set greater than or equal to the displayed scan line length. For example, a 640x480, 24-bit, graphics mode
has a displayed scan line length of 640*3 or 1920 bytes. It is fairly typical to set this mode to 2048 bytes so that a 64K bank
boundary does not cross in the middle of a pixel (an R, G, B triplet).
On a Set Scan Line Length subfunction call, if the desired width is larger than the maximum available, then this function will
fail and AH will be set to 02h on exit.
13.2.7.1 Subfunction 00h: Set Scan Line Length in Pixels
Passed:
Returns:
13.2.7.2 Subfunction 01h: Get Scan Line Length
Passed:
Parameter Description
AH 4Fh
AL 05h
DL 01h
BL Window number:
0 = Window A
1 = Window B
Parameter Description
AX VBE return status
DX Bank number
Parameter Description
AH 4Fh
AL 06h
BL 00h
CX Desired width in pixels
Parameter Description
AX VBE return status
BX Bytes per scan line
CX Actual pixels per scan line (truncated to nearest)
DX Maximum number of scan lines
Parameter Description
AH 4Fh
AL 06h
BL 01h