American Megatrends Super Voyager LPX, User Manual

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Super Voyager LPX ISA Motherboard User's Guide
Super VGA Functions,
Continued
Super VGA Mode Numbers
Standard VGA mode numbers are seven bits wide and range from 00h to
13h. OEMs have defined extended video modes from 14h to 7Fh. Video
modes from 80h to FFh cannot be used since VGA BIOS function 00h
(Set video mode) interprets bit 7 as a flag to clear or not clear video
memory.
VESA video mode numbers are 15 bits wide. To initialize SVGA mode,
its number is passed in BX to INT 10h function 02h Set SVGA mode.
The format of VESA mode numbers is:
Bit 15 Reserved
Bits 14-9 Must be 0. Reserved for future expansion.
Bit 8-0
Mode number
If bit 8 is not 0, this is not a VESA-defined mode.
If bit 8 is 1, this is a VESA-defined mode.
Extended VGA BIOS
Several new BIOS calls have been defined to support SVGA modes. For
maximum compatibility with the standard VGA BIOS, these calls are
grouped under one function number, 4Fh. This number is passed in AH
to INT 10h.
Status Information
Every function returns status information in the AX register. The format
of the status word is as follows:
AH Contents AL Contents Meaning
4Fh Function is supported.
not 4Fh Function is not supported.
00h Function call was successful.
not 00h Function call was
unsuccessful.