Computer Architecture and Assembly Language Programming || program to color the entire screen in two halves.

 Question: Write an assembly language program to color the entire screen in two halves. Upon running the program, the left half of the screen should become green when the spacebar key is pressed. After that, when the spacebar key is released, the right half of the screen should become blue. The program should terminate when the Enter key is pressed.

Solution:

1)      Complete assembly language program.

[org 0x100]

jmp start

 

OLisr: dd 0

 

kbisr:

 

push ax

push es

mov ax,0xb800

mov es,ax

in al, 0x60

cmp al, 0x39

jne nxtcmp

mov ah,06h

xor al,al

xor cx, cx

 mov dx, 1827h

mov bh, 2eh

int 10h

jmp nomatch

 

nxtcmp:

cmp al,0xB9

jne nomatch

mov ah, 06h

mov cx, 0027h

mov dx, 184fh

mov bh, 1eh

int 10h

 

nomatch:

pop es

pop ax

jmp far [cs:OLisr]

 

start:

xor ax,ax

mov es,ax

mov ax,[es:9*4]

mov [OLisr],ax

mov ax,[es:9*4+2]

mov [OLisr+2],ax

cli

mov word [es:9*4],kbisr

mov [es:9*4+2],cs

sti

L1:

mov ah,0

int 0x16

cmp al,13

jne L1

mov ax, 0x4c00

int 0x21 

1)      Screenshot of the compilation step. 

Screenshot of the final output.