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AX = 4F00h ES:DI -> buffer for SuperVGA information (see #00077)
Return:
AL = 4Fh if function supported AH = status 00h successful ES:DI buffer filled 01h failed ---VBE v2.0--- 02h function not supported by current hardware configuration 03h function invalid in current video mode
Desc: Determine whether VESA BIOS extensions are present and the capabilities supported by the display adapter
See Also:
AX=4E00h - AX=4F01h - AX=7F00h"SOLLEX" - AX=A00
Index:
Format of SuperVGA information:
Offset Size Description (Table 00077)
00h 4 BYTEs (ret) signature ("VESA")
(call) VESA 2.0 request signature ("VBE2"), required to receive
version 2.0 info
04h WORD VESA version number (one-digit minor version -- 0102h = v1.2)
06h DWORD pointer to OEM name
"761295520" for ATI
0Ah DWORD capabilities flags (see #00078)
0Eh DWORD pointer to list of supported VESA and OEM video modes
(list of words terminated with FFFFh)
12h WORD total amount of video memory in 64K blocks
---VBE v1.x ---
14h 236 BYTEs reserved
---VBE v2.0 ---
14h WORD OEM software version (BCD, high byte = major, low byte = minor)
16h DWORD pointer to vendor name
1Ah DWORD pointer to product name
1Eh DWORD pointer to product revision string
22h WORD (if capabilities bit 3 set) VBE/AF version (BCD)
0100h for v1.0P
24h DWORD (if capabilities bit 3 set) pointer to list of supported
accelerated video modes (list of words terminated with FFFFh)
28h 216 BYTEs reserved for VBE implementation
100h 256 BYTEs OEM scratchpad (for OEM strings, etc.)
Notes:
The list of supported video modes is stored in the reserved portion of
the SuperVGA information record by some implementations, and it may
thus be necessary to either copy the mode list or use a different
buffer for all subsequent VESA calls.
Not all of the video modes in the list of mode numbers may be
supported, e.g. if they require more memory than currently installed
or are not supported by the attached monitor. Check any mode you
intend to use through AX=4F01h first..
The 1.1 VESA document specifies 242 reserved bytes at the end, so the
buffer should be 262 bytes to ensure that it is not overrun; for
v2.0, the buffer should be 512 bytes.
The S3 specific video modes will most likely follow the FFFFh
terminator at the end of the standard modes. A search must then
be made to find them, FFFFh will also terminate this second list.
In some cases, only a "stub" VBE may be present, supporting only
AX=4F00h; this case may be assumed if the list of supported video
modes is empty (consisting of a single word of FFFFh)
Bitfields for VESA capabilities:
Bit(s) Description (Table 00078)
0 DAC can be switched into 8-bit mode
1 non-VGA controller
2 programmed DAC with blank bit (i.e. only during blanking interval)
3 (VBE v3.0) controller supports hardware stereoscopic signalling
3 controller supports VBE/AF v1.0P extensions
4 (VBE v3.0) if bit 3 set:
=0 stereo signalling via external VESA stereo connector
=1 stereo signalling via VESA EVC connector
4 (VBE/AF v1.0P) must call EnableDirectAccess to access framebuffer
5 (VBE/AF v1.0P) controller supports hardware mouse cursor
6 (VBE/AF v1.0P) controller supports hardware clipping
7 (VBE/AF v1.0P) controller supports transparent BitBLT
8-31 reserved (0)
See Also:
#00077 - AX=4F09h
Installation check;VESA SuperVGA
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