INT 10,1B - Video BIOS Functionality and

State Information (MCGA/VGA)

	AH = 1B
	BX = implementation type (must be zero)
	ES:DI = pointer to 64 byte buffer


	on return:
	AL = 1B
	ES:DI = pointer to updated buffer  (see below)


	- returns static and dynamic information about the current
	  state and capabilities of the current video system
	- bytes 0-3 of the dynamic data table at ES:DI contain a far
	  pointer to the video static information table

Video BIOS Dynamic Functionality State Table (MCGA/VGA)

	Dynamic Video State Table

	00  dword   address of static functionality table
	04  byte    video mode
	05  word    number of columns
	07  word    length of displayed video buffer (# bytes)
	09  word    start address of upper left corner of video buffer
	0B  16bytes cursor position table for 8 pages (col,row)
	1B  byte    cursor end line
	1C  byte    cursor start line
	1D  byte    active video page
	1E  word    I/O port for CRTC address register
	20  byte    current value of CRTC 3x8 register
	21  byte    current value of CRTC 3x9 register
	22  byte    number of displayed character rows
	23  word    height of character matrix (points)
	25  byte    active display combination code
	26  byte    inactive display combination code
	27  word    number of displayed colors (mono = 0)
	29  byte    number of supported video pages
	2A  byte    raster scan lines 0=200, 1=350, 2=400, 3=480
	2B  byte    text character table used
	2C  byte    text character table used
	2D  byte    other state information:

		|7|6|5|4|3|2|1|0| State Information byte at offset 2D
		 | | | | | | | `--- 1 = all modes active (MCGA always 0)
		 | | | | | | `---- 1 = gray scale summing enabled
		 | | | | | `----- 1 = monochrome display attached
		 | | | | `------ 1 = default palette loading disabled
		 | | | `------- 1 = cursor emulation enabled
		 | | `-------- 1 = blinking attribute enabled
		 `----------- 1 = reserved

	2E 3bytes   reserved
	31  byte    video RAM available 0=64K, 1=128K, 2=192K, 3=256K
	32  byte    save area status

		|7|6|5|4|3|2|1|0| Save Area Status
		 | | | | | | | `--- 1 = two text char sets are active
		 | | | | | | `---- 1 = dynamic save area is active
		 | | | | | `----- 1 = text char set override is active
		 | | | | `------ 1 = graphics char set is override active
		 | | | `------- 1 = palette override is active
		 | | `-------- 1 = display combination code ext. active
		 `----------- 1 = reserved

	33  dword   reserved

Video BIOS Static Functionality Table (EGA/VGA)

		|7|6|5|4|3|2|1|0| Video modes supported, byte at offset 00
		 | | | | | | | `--- 1 = mode 0
		 | | | | | | `---- 1 = mode 1
		 | | | | | `----- 1 = mode 2
		 | | | | `------ 1 = mode 3
		 | | | `------- 1 = mode 4
		 | | `-------- 1 = mode 5
		 | `--------- 1 = mode 6
		 `---------- 1 = mode 7

		|7|6|5|4|3|2|1|0| Video modes supported, byte at offset 01
		 | | | | | | | `--- 1 = mode 8
		 | | | | | | `---- 1 = mode 9
		 | | | | | `----- 1 = mode A
		 | | | | `------ 1 = mode B
		 | | | `------- 1 = mode C
		 | | `-------- 1 = mode D
		 | `--------- 1 = mode E
		 `---------- 1 = mode F

		|7|6|5|4|3|2|1|0| Video modes supported, byte at offset 02
		 | | | | | | | `--- 1 = mode 10
		 | | | | | | `---- 1 = mode 11
		 | | | | | `----- 1 = mode 12
		 | | | | `------ 1 = mode 13
		 `------------- reserved

	03  dword  reserved
	07  byte   scan lines supported in text modes

		|7|6|5|4|3|2|1|0| Scan lines supported, byte at offset 07
		 | | | | | | | `--- 1 = 200 lines
		 | | | | | | `---- 1 = 350 lines
		 `--------------- 1 = 400 lines

	08  byte   max number of displayable text character sets
	09  byte   # of text definition tables in char generator RAM
	0A  byte   other capability flags

		|7|6|5|4|3|2|1|0| Other flags, byte at offset 0A
		 | | | | | | | `--- 1 = all modes (0 on MCGA)
		 | | | | | | `---- 1 = gray scale summing
		 | | | | | `----- 1 = character set loading
		 | | | | `------ 1 = default palette loading
		 | | | `------- 1 = cursor emulation
		 | | `-------- 1 = 64 color palette
		 | `--------- 1 = video DAC loading
		 `---------- 1 = DAC controlled by ACCS

	0B  byte   other capability flags

		|7|6|5|4|3|2|1|0| Other flags, byte at offset 0B
		 | | | | | | | `--- 1 = light pen support
		 | | | | | | `---- 1 = save/restore video state
		 | | | | | `----- 1 = blinking/background intensity
		 | | | | `------ 1 = display combination code
		 `------------- reserved

	0C  word   reserved
	0E  byte   save area capabilities

		|7|6|5|4|3|2|1|0|  save area capabilities at offset 0E
		 | | | | | | | `---- 1 = multiple text character sets
		 | | | | | | `----- 1 = dynamic save area
		 | | | | | `------ 1 = text character set override
		 | | | | `------- 1 = graphics character set override
		 | | | `-------- 1 = palette override
		 | | `--------- 1 = display combination code extension
		 `------------ reserved

	0F  byte    reserved