;how to take and show a message

.model small
.stack 100h
.data
;declare variable
msg db 'my ID 21300046!$'

.code
main proc
mov ax, @data
mov ds, ax

lea dx,msg
mov ah, 9
int 21h

mov ah, 4ch
int 21h
main endp
end main



;take input from keyboard and show it

.model small
.stack 100h
.data
msg db 'enter your string: $'

.code
main proc
mov ax, @data
mov ds, ax

lea dx,msg
mov ah, 9
int 21h

mov ah, 1
int 21h
mov bl, al

mov ah, 2
mov dl, 0dh
int 21h
mov dl, 0ah
int 21h

mov dl, bl
int 21h

mov ah,4ch
int 21h

main endp
end main



;addition of single digit

.model small
.stack 100h
.data

.code
main proc
mov ah, 1
int 21h
mov bl,al

mov ah,1
int 21h
add bl,al
sub bl,'0'

mov ah,2
mov dl,bl
int 21h

mov ah,4ch
int 21h

main endp
end main



;addition of multi digit

.model small
.stack 100h
.data
digit1 db 0ah, 0dh, "enter first digit: $"
digit2 db 0ah, 0dh, "enter second digit: $"
result db 0ah, 0dh, "result is $"

.code
main proc
mov ax, @data
mov ds, ax

lea dx, digit1
mov ah, 09h
int 21h

mov ah,01h
int 21h

sub al, 30h
mov bh, al

mov ah, 01h
int 21h

sub al, 30h
mov bl, al

lea dx, digit2
mov ah, 09h
int 21h

mov ah, 01h
int 21h

sub al, 30h
mov ch, al

mov ah, 01h
int 21h

sub al, 30h
mov cl, al

add bl, cl

mov al, bl
mov ah, 00h
aaa

mov cl, al
mov bl, ah

add bl, bh
add bl, ch

mov al, bl
mov ah,00h
aaa

mov bx,ax

mov dx, offset result
mov ah, 09h
int 21h

mov dl, bh
add dl, 30h
mov ah, 02h
int 21h

mov dl, bl
add dl, 30h
mov ah, 02h
int 21h

mov dl, cl
add dl, 30h
mov ah, 02h
int 21h
exit:
mov ah, 04ch
int 21h

main endp
end main



;subt of single digit

.model small
.stack 100h
.data

.code
main proc
mov ah, 1
int 21h
mov bl,al

mov ah,1
int 21h
sub bl,al
add bl,'0'

mov ah,2
mov dl,bl
int 21h

mov ah,4ch
int 21h

main endp
end main



;subt of multi digit

.model small
.stack 100h
.data
msg1 db  'enter first number: ', '$'
msg2 db  'enter second number: ', '$'
msg3 db  'the output is: ', '$'
crlf db 0dh, 0ah, '$'

num1digit1 db ?
num1digit2 db ?
num2digit1 db ?
num2digit2 db ?

.code
main proc
mov ax, @data
mov ds, ax

mov ah, 9
lea dx, msg1
int 21h

mov ah,1
int 21h
mov num1digit1, al
sub num1digit1, 30h

mov ah, 1
int 21h
mov num1digit2, al
sub num1digit2, 30h

mov ah, 9
lea dx, crlf
int 21h

mov ah, 9
lea dx, msg2
int 21h

mov ah, 1
int 21h
mov num2digit1, al
sub num2digit1, 30h

mov ah, 1
int 21h
mov num2digit2, al
sub num2digit2, 30h

mov ah, 9
lea dx, crlf
int 21h

mov ah, 9
lea dx, msg3
int 21h

mov ah, 2
mov cl, num1digit1
sub cl, num2digit1
mov dl, cl
add dl, 30h
int 21h

mov ah, 2
mov cl, num1digit2
sub cl, num2digit2
mov dl, cl
add dl, 30h
int 21h

mov ah, 4ch
int 21h

main endp
end main



;9-0 in reverse system

.model small
.stack 100h
.data
msg db 0ah, 0dh, "9-0 in reverse system: $"

.code
main proc
mov ax, @data
mov ds, ax

lea dx, msg
mov ah, 9
int 21h

mov cx, 10

mov ah, 2
mov dl, 57

@loop:
int 21h

dec dl
dec cx
jnz @loop

mov ah, 4ch
int 21h

main endp
end main


;print @, read 2 dec digit and add them

.model small
.stack 100h
.data
msg db 'THE SUM OF$'
msg1 db ' $'
msg2 db 'AND$'
msg3 db 'IS$'
.code
main proc

mov dl,'@'
mov ah,2
int 21h

mov ah,1
int 21h

mov bl,al

mov ah,1
int 21h

mov cl,al

mov ah,2
mov dl,0dh
int 21h
mov dl,0ah
int 21h

mov ax,@data
mov ds,ax
lea dx,msg
mov ah,9
int 21h

lea dx,msg1
mov ah,9
int 21h

mov ah,2
mov dl,bl
int 21h

lea dx,msg1
mov ah,9
int 21h

lea dx,msg2
mov ah,9
int 21h

lea dx,msg1
mov ah,9
int 21h

mov ah,2
mov dl,cl
int 21h

lea dx,msg1
mov ah,9
int 21h

lea dx,msg3
mov ah,9
int 21h

lea dx,msg1
mov ah,9
int 21h

add bl,cl
sub bl,48d

mov dl,bl
mov ah,2
int 21h

mov ah,4ch
int 21h

main endp
end main



;ENTER THREEE INITIALS: JFK 
;Output Will be
;       J
;       F 
;       K


.model small
.stack 100h
.data
msg db 'ENTER THREE INITIAL: $'
.code
main proc

mov ax,@data ;initialize data segment
mov ds,ax
lea dx,msg
mov ah,9
int 21h

mov ah,1
int 21h
mov bl,al

mov ah,1
int 21h
mov cl,al

mov ah,1
int 21h
mov bh,al

mov ah,2
mov dl,0dh ;caariage return
int 21h
mov dl,0ah ;new line
int 21h

mov ah,2
mov dl,bl
int 21h

mov dl,0dh
int 21h
mov dl,0ah
int 21h

mov ah,2
mov dl,cl
int 21h

mov dl,0dh
int 21h
mov dl,0ah
int 21h

mov ah,2
mov dl,bh
int 21h

mov ah,4ch
int 21h

main endp
end main



;Upper case to lower case

.model small
.stack 100h
.data

msg db 'Enter an uppercase letter: $'
val db ?
str db 0ah,0dh,'After convert the uppercase letter into lowercase letter: '
ans db ?
finish db '$'

.code
main proc

mov ax,@data
mov ds,ax

mov ah,9
lea dx,msg
int 21h

mov ah,1
int 21h
mov val,al

add al,20h
mov ans,al

mov ah,9
lea dx,str
int 21h

mov ah,4ch
int 21h

main endp
end main




;Odd(o) even (e)

.model small
.stack 100h
.data
msg1 db 10, 13, 'This is an odd number$'
msg2 db 10, 13, 'This is an even number$'
.code
main proc
mov ax, @data
mov ds, ax
mov ah, 1
int 21h

cmp al, 1
je odd_
cmp al, 3
je odd_

cmp al, 2
je even_
cmp al, 4
je even_
odd_:
lea dx, msg1
mov ah, 9
int 21h
jmp end_case
even_:
lea dx, msg2
mov ah, 9
int 21h
jmp end_case
end_case:
mov ah, 4ch
int 21h
main endp
end main



;yx = xy

.model small
.stack 100h
.data
msg db 10,13,'?$'
msg1 db 10,13,'Enter two letter=$'
msg2 db 10,13,'Output is=$'
.code
main proc
mov ax,@data
mov ds,ax

lea dx,msg

mov ah,9
int 21h

lea dx,msg1
mov ah,9
int 21h

mov ah,1
int 21h
mov bl,al

mov ah,1
int 21h
mov cl,al

lea dx,msg2
mov ah,9
int 21h

cmp bl,cl
ja go ; if bl>cl

mov dl,bl
mov ah,2
int 21h

mov dl,cl
int 21h

jmp exit

go:
mov dl,cl
mov ah,2
int 21h

mov dl,bl
int 21h
jmp exit

exit:
mov ah,4ch
int 21h
main endp
end main



;ttaannvviirr(Repeat loop)

.model small
.stack 100h
.data
.code
main proc

mov ax,@data
mov ds,ax

repeat:

mov ah,1
int 21h

cmp al,20h
je end_

mov ah,2
mov dl,al
int 21h

jmp repeat

end_:

mov ah,4ch
int 21h
main endp
end main



;if uppercase the display it

.model small
.stack 100h
.data

prompt  db  'Enter the character : $'
msg_1   db  'The input letter is : $'
msg_2   db  'The input character is not an upper case letter.$'

.code
main proc
mov ax, @data
mov ds, ax

lea dx, prompt
mov ah, 9
int 21h

mov ah, 1
int 21h

mov bl, al
mov ah, 2
mov dl, 0dh
int 21h

mov dl, 0ah
int 21h

cmp bl, "A"

jb @display

cmp bl, "Z"

ja @display

lea dx,msg_1
mov ah, 9
int 21h

mov ah, 2
mov dl, bl
int 21h

jmp @exit

@display:
lea dx,msg_2
mov ah, 9
int 21h

@exit:

mov ah, 4ch
int 21h
main endp
end main



;ABCDEFGHIJKLMNOPQRSTUVWXYZ

.model small
.stack 100h
.data
.code
main proc
mov cx, 26
mov ah, 2
mov dl, 65

L1:
int 21h
inc dl
loop L1
mov dl, 10
mov ah,2
INT 21h
mov dl, 13
mov ah,2
INT 21h
mov cx, 26
mov dl, 97
mov ah, 2

mov ah,4ch
INT 21h
main endp
end main