SPC8104 S-MOS Systems, SPC8104 Datasheet - Page 148

• Manufacturer Part Number: SPC8104
• Description: VGA LCD CONTROLLER
• Manufacturer: S-MOS Systems

Appendix C BIOS USE OF INTERNAL SCRATCH BITS
The BIOS uses scratch bits to store information, which has no equivalent in a standard IBM com-
patible BIOS.
typically processed at a mode set.
This is an index into a table of possible VESA modes. If all bits are zero, no VESA mode is cur-
rently active. The remaining seven combinations are indexes into a table of supported VESA
modes. This table has the following values: 00 = no VESA mode, 01 = first VESA mode as
returned by function 0, 02 = second VESA mode as returned by function 0, 03 = third VESA
mode, etc. as returned by function 0.
BIOS Functional Specification
SP2-42
These scratch registers should not be programmed directly, using SOLLEX calls is recom-
mended instead, as bit locations may change without notice.
Auxiliary Register D
VESA Mode Index
S-MOS Systems, Inc. • Tel: [phone] • Fax: [phone] • http://www.smos.com
Changing a bit state has no immediate effect on the video state, scratch bits are
7 6 5 4 3 2 1 0
X15-SP-002-03
Reserved
Current Mode Set By VESA / IBM
VESA Mode Index
412-1.0
SPC8104