REVERSE -> ESREVER

;THANKS TO MY PROFESSOR FOR THE PROBLEM
.model tiny
.code
org 100h

begin: jmp start
msg1 db "REVERSE",0ah,"$"
msg2 db 8 dup(20h),"$";8 is the number of characters including the space

start proc
lea si,msg1[7];7 is the number of characters
lea di,msg2[0]
mov cx,8;8 is the number of characters including the space

prog: mov al,[si]
mov [di],al
dec si
inc di
dec cx
jnz prog

mov ah,09h
lea dx,msg1
int 21h

mov ah,09h
lea dx,msg2
int 21h

mov ah,07h
int 21h

mov ax,4c00h
int 21h

start endp
end begin

ASCII characters

;This program displays all ascii characters
;from IBM PC by Peter Abel (5th edition)
.model small
.stack 64
.data

char_ctr db 00
col db 24
row db 04
mode db ?
.286

.code

a10main proc near
mov ax,@data
mov ds,ax
mov es,ax
call b10mode
call c10clear
a20:
call d10cursor
call e10disply
cmp char_ctr,0ffh
je a30
inc char_ctr
add col,02
cmp col,56
jne a20
inc row
mov col,24
jmp a20
a30:
mov ah,10h
int 16h
mov ah,00h
mov al,mode
int 10h
mov ax,4c00h
int 21h
a10main endp

b10mode proc near
mov ah,0fh
int 10h
mov mode,al
mov ah,00h
mov al,03
int 10h
ret
b10mode endp

c10clear proc near
pusha
mov ah,08h
int 10h
mov bh,ah
mov ax,0600h
mov cx,0000
mov dx,184fh
int 10h
mov ax,0610h
mov bh,5Dh
mov cx,0418h
mov dx,1336h
int 10h
popa
ret
c10clear endp

d10cursor proc near
pusha
mov ah,02h
mov bh,00
mov dh,row
mov dl,col
int 10h
popa
ret
d10cursor endp

e10disply proc near
pusha
mov ah,0ah
mov al,char_ctr
mov bh,00
mov cx,01
int 10h
popa
ret
e10disply endp
end a10main

Reverse Keyboard

Example if capslock is on, A will be a.. and if off a will be A

.model small
.stack 50
.data
msg db "Enter a character: $"
.code
main proc
mov ax,@data
mov ds,ax
mov ah,09
mov dx,offset msg
int 21h

start: mov ah,07
int 21h

cmp al,0dh
je exit

cmp al,41h
je smol

cmp al,41h
ja sa

cmp al,41h
jb start


cmp al,5ah
je smol


cmp al,5ah
jb smol

cmp al,61h
je cap

cmp al,61h
ja cap

cmp al,7ah
je cap

cmp al,7ah
ja start

cmp al,7ah
jb ca



sa: cmp al,5ah
je smol

cmp al,5ah
jb smol



ca: cmp al,61h
je cap

cmp al,61h
ja cap

cmp al,61h
jb start

cap: sub al,20h
jmp disp


smol: add al,20h
jmp disp

disp: mov ah,02
mov dl,al
int 21h
jmp start

exit: mov ax,4c00h
int 21h

main endp
end main

Numbers only

;This program accepts only numbers. Press enter to quit.


stak segment para stack 'stack'
db 100 dup (0)
stak ends

dta segment
msg1 db "Enter a number: $"
dta ends

kod segment
main proc

assume ss:stak, ds:dta, cs:kod

mov ax,dta
mov ds,ax
mov ah,09
mov dx,offset msg1
int 21h

start: mov ah,07
int 21h

cmp al,0dh
je exit

cmp al,30h
jb start

cmp al,39h
ja start


disp: mov ah,02
mov dl,al
int 21h
jmp start

exit: mov ax,4c00h
int 21h

main endp
kod ends
end main

Hello World! (Prints a string)

;prints a string
stak segment para stack 'stack'
db 50 dup(0)
stak ends

dta segment
msg db"Hello World!$"
dta ends

kod segment
prok proc
assume ss:stak, ds:dta, cs:kod

mov ax,dta
mov ds,ax

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

mov ah,07
int 21h

mov ax,4c00h
int 21h
prok endp
kod ends
end prok