; draw 1 blue pixel to screen
Title base program for graphics example
.model small
.stack 100h

.data


.code
main proc
 ; load data segment
  mov ax, @data
  mov ds, ax

 ; get current video mode
  mov ah, 0fh
  int 10h
  push ax

 ; set video mode
  mov ah, 00h
  mov al, 0Dh
  int 10h


  ;Function 0Ch: Write pixel dot
  ;this function uses values from registers as follows
  ;AL : color of the pixel
  ;BH : page number
  ;CX : column
  ;DX : row

 ; draw a sample pixel

  mov ah, 0Ch
  mov al, 1100b
  mov bh, 0
  mov cx, 100
top1:

  mov dx, 10
  int 10h
  mov dx, 100
  int 10h
  dec cx
  cmp cx, 10
jae top1

mov ah, 0Ch
mov al, 1010b
mov dx, 100
mov bh, 0
top2:



  mov cx, 10

  int 10h
  mov cx, 100
  int 10h
  dec dx
  cmp dx, 10

jae top2

mov dx, 99
mov ah, 0Ch
mov al, 1111b
mov bh, 0

top3:

mov cx, 99

top4:

int 10h
dec cx
cmp cx, 11
jae top4

dec dx
cmp dx, 11
jae top3

 ; wait for key
  mov ah, 10h
  int 16h


 ; restore video mode
  pop ax
  mov ah, 00h
  int 10h

 ; exit program
  mov ax, 4C00h
  int 21h

main endp
end main