Uppercase to Lowercase

.MODEL SMALL
.STACK 100H
.DATA
 
  M1 DB 0DH, 0AH, "ENTER THE UPER CASE LETTER::$"
  M2 DB 0DH, 0AH, "THE LOWER CASE LETTER IS::$"
  SUM DW 0

.CODE
  MAIN PROC
  MOV AX, @DATA
  MOV DS, AX

LEA DX,M1
MOV AH,9
INT 21H

MOV AH,1
INT 21H

MOV AL,A
ADD AL,20H
INT 21H

LEA DX,M2
MOV AH,9
INT 21H

MOV AH,2
MOV DL,BL
INT 21H

MOV AH, 4CH
INT 21H

MAIN ENDP
END MAIN

reverse program

.MODEL SMALL
.STACK 100H
.DATA
MSG1 DB "Enter the test::$"
MSG2 DB ODH.OAH,"The reverse is::$"
.CODE
MAIN PROC
MOV AX,@DATA
MOV DS,AX
XOR CX,AX
MOV AH,9
LEA DX,MSG1
INT 21H
MOV AH,1
INT 21H
WHILE:CMP AL,ODH
JE DISPLAY
PUSH AX INC CX
INT 21H
JMP WHILE
Display:MOV AH,9
LEA DX,MSG2
JNT 21H
JCXZ
TOP:MOV AH,2
POP DX
INT 21H
LOOP TOP
EXIT:MOV AH,4ch
INT 21H
MAIN ENDP
END MAIN

ASCI to Binary

.MODEL SMALL
.STACK 100H
.DATA DB
M1 DB "Enter the Character::$"
M2 DB ODH,OAH,"The binary is::$"

MAIN PROC
MOV AX,@DATA
MOV DS,AX

MOV AH,1
INT 21H
MOV BL,AL
MOV CX,0
TOP:CMP CX,8
JE EXIT
SHL BL,1
JC PRINT1
MOV DL,'0'
MOV AH,2
INT 21H
PRINT 1:
MOV DC,1
MOV AH,2
INT 21H
INC CX
JMP TOP
INC CX
JMP TOP
MOV AH,4ch
INT 21H
MAIN ENDP
END MAIN
Exit:MOV AH,4CH
INT 21H
MAIN END