Program for String manipulations for 8086

1. Length of the string

Aim:

To write an assembly language program to find the length of the given string.

Tools:

PC installed with TASM.

Program:

ASSUME CS : CODE, DS : DATA
CODE SEGMENT
MOV AX, DATA
MOV DS, AX
MOV AL, ’$’
MOV CX, 00H
MOV SI, OFFSET STR1
BACK : CMP AL, [SI]
JE GO
INC CL
INC SI
JMP BACK
GO : MOV LENGTH, CL
HLT
CODE ENDS
DATA SEGMENT
STR1 DB ‘STUDENT BOX OFFICE$’
LENGTH DB ?
DATA ENDS 
END

Flow Chart:

Result:

Input:

STR (DS : 0000H) = STUDENT BOX OFFICE

Output:

LENGTH = 18

2. Display the string

Aim:

To write an assembly language program to display the given string.(DOS PROGRAMMING)

Software required:

TASM TURBO ASSEMBLER

Program:

ASSUME CS : CODE, DS : DATA
CODE SEGMENT
MOV AX, DATA
MOV DS, AX
MOV AH, 09H
MOV DX,OFFSET MSG
INT 21H
MOV AH, 4CH
INT 21H
CODE ENDS
DATA SEGMENT
MSG DB 0DH, 0AH, "WELCOME TO MICROPROCESSORS LAB", 0DH, 0AH, "$" 
DATA ENDS
END

Result:

WELCOME TO MICROPROCESSORS LAB

3. Reverse the string

Aim:

To write an assembly language program to reverse the given string.

Sofware required:

TASM TURBO ASSEMBLER

Program:

ASSUME CS : CODE, DS : DATA
CODE SEGMENT
MOV AX, DATA
MOV DS, AX
MOV CL, COUNT
MOV SI, OFFSET STR1
MOV DI, COUNT - 1
BACK:MOV AL, [SI]
XCHG [DI], AL
MOV [SI], AL
INC SI
DEC DI
DEC CL
JNZ BACK
HLT
CODE ENDS
DATA SEGMENT
STR1 DB ‘MPMC$’
COUNT EQU 04H
STR2 DB DUP (0)
DATA ENDS 
END

Flow Chart:

Result:

Input:

STR1 (DS:0000H)  =  

Output:

STR1 (DS:0004H) =