INT 10H Reference (VGA Control)

1) AH=00H - Set video mode

Description : This functions clears the screen and changes the video mode to the one that stored in AL

Example :

MOV AH, 00H
MOV AL, 01H
;01H : 40x25 Text, 8 Pages, 16 Colors
;03H : 80x25 Text, 8 Pages, 16 Colors (The default mode)
;13H : 320x200 Graphics , 1 Page, 256 Colors
INT 10H

2) AH=01H - Cursor appearance 

Description : Set the cursor size by setting its starting and ending lines

Example :

MOV AH, 01H
MOV CH, ;Start line (from 0 to 7)  use ADD CH, 20h to hide the cursor
MOV CL, ;End line

INT 10H

3) AH=02H - Set cursor position

Description : Change the cursor position to a specific position. Works only with text mode, Set BH=00h for graphics mode

Example :

MOV AH, 02H
MOV BH, ;The current display page
MOV DH, ;ROW. 00H is the topmost
MOV DL, ;COLUMN. 00H is the leftmost

INT 10H

Note : The video hardware sets a custom cursor for each display page, and the cursor will move if the current BH value = the current display page.
If you set DH or DL to a value out of the screen, the cursor will disappear.

4) AH=0CH - Write pixels

Description : This function used to write a specified color to a specified pixel. You can use a loop to draw any desired shape

Example :

MOV AH, 0DH
MOV BH, ;Display page
MOV DX, ;Row
MOV CX, ;Column
MOV AL, ;Color code in binary

INT 10H

5) AH=0DH - Read pixels

Description : Returns the color of a specified pixel, valid for all graphic modes

Example :

MOV AH, 0DH
MOV BH, ;Display page
MOV DX, ;Row
MOV CX, ;Column

INT 10H

;AL = Color code

TO BE CONTINUED