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