Specifications
AMD Geode™ GeodeROM Functional Specification 187
Video BIOS Support
32087C
13.1.19.5 Subfunction 32h: Enable/Disable Video Subsystem
Enables or disables the video subsystem. All I/O and memory accesses are affected.
Passed:
Returns:
13.1.19.6 Subfunction 33h: Enable/Disable Summing to Gray Scales
Causes all RAMDAC operations to load “as is” or to sum the color values to a shade of gray. Setting this flag has an
effect the next time the RAMDAC is loaded (includes mode sets). The relative shade of gray is based on 30% red, 59%
green, and 11% blue.
Passed:
Returns:
13.1.19.7 Subfunction 34h: Enable/Disable Cursor Emulation
Calling this subfunction enables or disables the cursor type emulation for Function 01h (Set Cursor Type on page 166).
The default is for emulation to be enabled. When emulated, the cursor follows these general rules:
• Bit 5 = 1: No cursor
• Start scan < end scan < = 3: Overbar cursor
• Start scan + 2 > = end scan: Underline cursor
• Start > = 2: Half block cursor
• Start < = 2: Full block cursor
• End < Start: Full block cursor
Parameter Description
AH 12h
AL Enable subsystem flag:
0 = Enable
1 = Disable
BL 32h
Parameter Description
AL 12h
Parameter Description
AH 12h
AL Enable gray scale flag:
0 = Enable
1 = Disable
BL 33h
Parameter Description
AL 12h