Int 10/AX=4F01h

VESA SuperVGA BIOS - GET SuperVGA MODE INFORMATION

AX = 4F01h
CX = SuperVGA video mode (see #04082 for bitfields)
ES:DI -> 256-byte buffer for mode information (see #00079)

Return:
AL = 4Fh if function supported
AH = status
00h successful
ES:DI buffer filled
01h failed

Desc: Determine the attributes of the specified video mode

See Also: AX=4F00h - AX=4F02h

Bitfields for VESA/VBE video mode number: Bit(s) Description (Table 04082) 15 preserve display memory on mode change 14 (VBE v2.0+) use linear (flat) frame buffer 13 (VBE/AF 1.0P) VBE/AF initializes accelerator hardware 12 reserved for VBE/AF 11 (VBE v3.0) user user-specified CRTC refresh rate values 10-9 reserved for future expansion 8-0 video mode number (0xxh are non-VESA modes, 1xxh are VESA-defined)

Format of VESA SuperVGA mode information: Offset Size Description (Table 00079) 00h WORD mode attributes (see #00080) 02h BYTE window attributes, window A (see #00081) 03h BYTE window attributes, window B (see #00081) 04h WORD window granularity in KB 06h WORD window size in KB 08h WORD start segment of window A (0000h if not supported) 0Ah WORD start segment of window B (0000h if not supported) 0Ch DWORD -> FAR window positioning function (equivalent to AX=4F05h) 10h WORD bytes per scan line ---remainder is optional for VESA modes in v1.0/1.1, needed for OEM modes--- 12h WORD width in pixels (graphics) or characters (text) 14h WORD height in pixels (graphics) or characters (text) 16h BYTE width of character cell in pixels 17h BYTE height of character cell in pixels 18h BYTE number of memory planes 19h BYTE number of bits per pixel 1Ah BYTE number of banks 1Bh BYTE memory model type (see #00082) 1Ch BYTE size of bank in KB 1Dh BYTE number of image pages (less one) that will fit in video RAM 1Eh BYTE reserved (00h for VBE 1.0-2.0, 01h for VBE 3.0) ---VBE v1.2+ --- 1Fh BYTE red mask size 20h BYTE red field position 21h BYTE green mask size 22h BYTE green field size 23h BYTE blue mask size 24h BYTE blue field size 25h BYTE reserved mask size 26h BYTE reserved mask position 27h BYTE direct color mode info

bit 0:
Color ramp is programmable

bit 1:
Bytes in reserved field may be used by application ---VBE v2.0+ --- 28h DWORD physical address of linear video buffer 2Ch DWORD pointer to start of offscreen memory 30h WORD KB of offscreen memory ---VBE v3.0 --- 32h WORD bytes per scan line in linear modes 34h BYTE number of images (less one) for banked video modes 35h BYTE number of images (less one) for linear video modes

36h BYTE linear modes:
Size of direct color red mask (in bits)

37h BYTE linear modes:
Bit position of red mask LSB (e.g. shift count)

38h BYTE linear modes:
Size of direct color green mask (in bits)

39h BYTE linear modes:
Bit position of green mask LSB (e.g. shift count)

3Ah BYTE linear modes:
Size of direct color blue mask (in bits)

3Bh BYTE linear modes:
Bit position of blue mask LSB (e.g. shift count)

3Ch BYTE linear modes:
Size of direct color reserved mask (in bits)

3Dh BYTE linear modes:
Bit position of reserved mask LSB 3Eh DWORD maximum pixel clock for graphics video mode, in Hz 42h 190 BYTEs reserved (0)

Note: While VBE 1.1 and higher will zero out all unused bytes of the buffer, v1.0 did not, so applications that want to be backward compatible should clear the buffer before calling

Bitfields for VESA SuperVGA mode attributes: Bit(s) Description (Table 00080) 0 mode supported by present hardware configuration 1 optional information available (must be =1 for VBE v1.2+) 2 BIOS output supported 3 set if color, clear if monochrome 4 set if graphics mode, clear if text mode ---VBE v2.0+ --- 5 mode is not VGA-compatible 6 bank-switched mode not supported 7 linear framebuffer mode supported 8 double-scan mode available (e.g. 320x200 and 320x240) ---VBE v3.0 --- 9 interlaced mode available 10 hardware supports triple buffering 11 hardware supports stereoscopic display 12 dual display start address support 13-15 reserved ---VBE/AF v1.0P--- 9 application must call EnableDirectAccess before calling bank-switching functions

See Also: #00079


Bitfields for VESA SuperVGA window attributes:

Bit(s)  Description     (Table 00081)
0      exists
1      readable
2      writable
3-7    reserved

See Also: #00079



(Table 00082)
Values for VESA SuperVGA memory model type:
00h    text
01h    CGA graphics
02h    HGC graphics
03h    16-color (EGA) graphics
04h    packed pixel graphics
05h    "sequ 256" (non-chain 4) graphics
06h    direct color (HiColor, 24-bit color)
07h    YUV (luminance-chrominance, also called YIQ)
08h-0Fh reserved for VESA
10h-FFh OEM memory models

See Also: #00079

Category: Video - Int 10h - V

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