Selects the current video display mode. Also selects the active video controller, if more than one video controller is present.
Call with:
AH = 00H
AL = video mode (see Notes)
Returns:
Nothing
Notes:
The video modes applicable to the various IBM machine models and video adapters are as follows:
Mode Resolution Colors Text/ MDA CGA PCjr EGA MCGA VGA
graphics
00H 40-by-25 16 text * * * * *
color burst
off
01H 40-by-25 16 text * * * * *
02H 80-by-25 16 text * * * * *
color burst
off
03H 80-by-25 16 text * * * * *
04H 320-by-200 4 graphics * * * * *
05H 320-by-200 4 graphics * * * * *
color burst
off
06H 640-by-200 2 graphics * * * * *
07H 80-by-25 2 (1) text * * *
08H 160-by-200 16 graphics *
09H 320-by-200 16 graphics *
0AH 640-by-200 4 graphics *
0BH reserved
0CH reserved
0DH 320-by-200 16 graphics * *
0EH 640-by-200 16 graphics * *
0FH 640-by-350 2 (1) graphics * *
10H 640-by-350 4 graphics * (2)
10H 640-by-350 16 graphics * (3) *
11H 640-by-480 2 graphics * *
12H 640-by-480 16 graphics *
13H 320-by-200 256 graphics * *
(1) Monochrome monitor only.
(2) EGA with 64 KB of RAM.
(3) EGA with 128 KB or more of RAM.
The presence or absence of color burst is only significant when a composite monitor is being used. For RGB monitors, there is no functional difference between modes 00H and 01H or modes 02H and 03H. On the CGA, two palettes are available in mode 04H and one in mode 05H.
On the PC/AT, PCjr, and PS/2, if bit 7 of AL is set, the display buffer is not cleared when a new mode is selected. On the PC or PC/XT, this capability is available only when an EGA or VGA (which have their own ROM BIOS) is installed.