1. Nhap vao 1 chuoi ky tu, in ra dao nguoc va bo khoang trang

Code:

.model small

.stack 100h

.data

msg1 db 'nhap vao mot chuoi: $'

msg2 db 13, 10, 'chuoi dao nguoc da duoc loai bo khoang trang la $'

.code

mov ax,@data

mov ds,ax

mov ah,9

lea dx,msg1

int 21h

mov cx,0

nhap:

mov ah,1

int 21h

cmp al, 32 ;co phai khoang trang

je nhap

cmp al,13 ; neu Enter thi ket thuc nhap

je thongbaoxuat

push ax

inc cx

jmp nhap

thongbaoxuat:

mov ah,9

lea dx,msg2

int 21h

xuat:

pop ax

mov dl,al

mov ah,2

int 21h

loop xuat

mov ah,4ch

int 21h

end

__________________________________________________________

2.Nhap vao mot chuoi, loai bo ky tu trang thua

.model small

.stack 100h

.data

msg1 db 'nhap vao mt chuoi: $'

msg2 db 13, 10, 'chuoi da duoc loai bo khoang trang la $'

chuoicuoi DB 80 dup('!')

.code

mov ax,@data

mov ds,ax

lea dx,msg1

lea si, chuoicuoi

cld ; dat co dinh huong tang

; thong bao thu 1

mov ah,9

int 21h

mov cx,0

nhap:

mov ah,1

int 21h

cmp al, 32 ;co phai khoang trang

je nhap

cmp al,13

je thongbaoxuat

;push ax

mov chuoicuoi[si], al

;inc cx

inc si

jmp nhap

thongbaoxuat:

inc cx

mov chuoicuoi[si], '$'

mov ah,9

lea dx,msg2

int 21h

xuat:

;pop ax

;mov dl,al

;mov ah,2

;int 21h

;loop xuat

mov ah, 9

lea dx, chuoicuoi

int 21h

mov ah,4ch

int 21h

end

---------------------------------------------------------------

3. Copy 1 chuoi............

.model small

.stack 100h

.data

s1 db 'abcd'

s2 db 4 dup (?)

.code

mov ax,@data

mov ds,ax

lea si,s1

lea di,s2+3

mov cx,4

cld

lap:

movsb

sub di,2

loop lap

mov ah,9

lea dx,s2

mov ah,4ch

int 21h

end

--------------------------------------------------------------

4.Dem so ky tu.....

demkytu proc

mov ax,0

repeat:

inc cx

mov bx,10

duv bx

cmp ax,0

jne repeat

output:

mov ah,2

add cx,30h

mov dl,cl

int 21h

demkytu endp

-------------------------------------------------------------

5.In dao nguoc cua so co nhieu chu so..........

.model small

.strack 100h

.data

.code

main proc

mov ax,100

mov ah,4ch

int 21h

main endp

output proc

mov cx,0

repeat:

inc cx

mov bx,10

div bx

push dx

cmp ax,0

jne repeat

in:

pop dx

mov ah,2

int 21h

loop in

ret

output endp

end main

--------------------------------------------------------------

6.Nhap vao 1 chuoi va cho biet tong ky tu da nhap.........

.data

s db 80 dup ('$')

.code

mov ax,@data

mov ds,ax

lea dx,s

mov ah,0Ah

int 21h

lea di,s+1

mov bl,[di]

cld,0

lea si,s+2

lap:

losb

mov dl,al

mov ah,2

int 21h

loop lap

------------------------------------------------------------------

7.Nhap vao 1 chuoi, nhap vao 1 ky tu va dem xem ky tu vua xuat hien trong chuoi bao nhieu

.data

s db 80 dup ('$')

.code

main proc

mov ax,@data

mov ds,ax

lea dx,3

mov ah,0Ah

int 21h

lea si,s

mov cx,[si]

mov ah,1

cld,0

add si,1

mov dl,0

lap:

losb

cmp bl,al

je dem

jmp boqua

dem:

inc dl

boqua:

loop lap

end main

-----------------------------------------------------

8.Nhap vao 1 day ky tu, khi nhan enter thi dung va xuat ra chuoi nguoc lai

.code

mov cx,0

lap_nhap:

mov ah,1

int 21h

cmp al,0dh

je xuat

push ax

inc cx

jmp lap_nhap

mov ah,2

xuat:

pop dx

int 21h

loop xuat

mov ah,4ch

int 21h

------------------------------------------------------

9.Nhap vao 1 day ky tu, ket thuc khi nhan enter va chuyen ra thap phan

.code

mov bx,0

input:

mov ah,1

int 21h

cmp dl,0dh

je stop_input

sub al,30h

mov ah,0

push ax

mov ax,10

mul bx

mov bx,ax

pop ax

add bx,ax

jmp input

stop_input:

ret

-----------------------------------------------------------

10.Nhap vao 1 ky tu, kiem tra lan luot co pai la ky tu so ko, pai thi in ra day so do

.model small

.stack 100h

.data

tb1 db 13, 10,'moi ban nhap vao ki tu $'

xuong_dong db 13, 10, '$'

.code

main proc

mov ax,@data

mov ds,ax

mov cx,0

call nhap

mov ah,4ch

int 21h

main endp

nhap proc

;mov bx,0

lea dx,tb1

mov ah,9

int 21h

mov ah,1

int 21h

cmp al,0dh

je bosung

cmp al,30h

jb nhap

cmp al,39h

jbe luu

; > '9'

cmp al,41h ;'A'

jb nhap

cmp al,5ah ;'Z'

jbe luu

; > 'Z'

cmp al,61h ;'a'

jb nhap

cmp al,7ah ;'z'

jbe luu

jmp nhap

luu:

mov ah,0

inc cx

push ax

jmp nhap

bosung:

;kiemtra

cmp cx,0

jne dem0

jmp kt

dem0:

;xuong dong truoc khi xuat ra

mov ah, 9

lea dx, xuong_dong

int 21h

dem:

pop ax

cmp al, 30h ;'0'

jb ko_in

cmp al,39h ;'9'

ja ko_in

;inc bx

mov ah, 2

mov dl, al

int 21h

ko_in:

loop dem

kt:

;mov ah,2

;int 21h

ret

nhap endp

end main

------------------------------------------------------

11.Tinh tong cua day 1+2+3...+n

.model small

.stack 100h

.data

tb1 db 'Nhap so n = $'

tb3 db 'Tong 1+2+...+n=$'

.code

main proc

mov bx,0

mov ax,@data

mov ds,ax

mov dx,offset tb1

mov ah,09

int 21h

xor bx,bx

nhap:

mov ah,1

int 21h

cmp al,0dh

je xuat

sub al,30h

mov ah,0

push ax

mov ax,0010d

mul bx

mov bx,ax

pop ax

add bx,ax

jmp nhap

xuat:

mov ah,2

mov dl,0ah

int 21h

mov dl,0dh

int 21h

mov dx,offset tb3

mov ah,09

int 21h

mov cx,bx

xor ax,ax

tinh:

add ax,cx

loop tinh

lap1:

xor dx,dx

mov bx,0010d

div bx

push dx

inc cx

cmp ax,0

je print1

jmp lap1

print1:

pop dx

mov ah,2

add dl,30h

int 21h

loop print1

main endp

mov ah,4ch

int 21h

end main

end.

---------------------------------------------------

12.Tong hai so co a+b

.model tiny

.stack 100h

.data

str1 db 'Nhap so thu nhat $'

str2 db 13,10,'Nhap so thu hai $'

str3 db 13,10,'Tong la $'

n dw 0

m dw 0

.code

mov ax,@data

mov ds,ax

mov ah,9

lea dx,str1

int 21h

nhap1:

mov ah,1

int 21h

;kiem tra xem so vua nhap vao co = 13(enter) ko?->neu la enter thi nhay den ra1 de nhap so thu 2

cmp al,13

je ra1

mov ah,0

sub al,'0'

mov cx,n;lap lai lan thu n

xchg ax,cx;hoan vi cx vao ax va nguoc lai

mov bx,10

mul bx

add ax,cx

mov n,ax

jmp nhap1

ra1:

mov ah,9

lea dx,str2

int 21h

nhap2:

mov ah,1

int 21h

cmp al,13

je ra2

mov ah,0

sub al,'0'

mov cx,m

xchg ax,cx

mov bx,10

mul bx

add ax,cx

mov m,ax

jmp nhap2

ra2:

mov ah,9

lea dx,str3

int 21h

mov bx,m

add bx,n

mov ax,bx

mov dx,0

mov cx,0

mov bx,10

chia:

div bx

push dx

inc cx

cmp ax,0

je inso

mov dx,0

jmp chia

inso:

pop dx

add dx,'0'

mov ah,2

int 21h

loop inso

mov ah,4ch

int 21h

end

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