To perform MESSAGE PASSING in 8051 Programming

MOV TMOD,#20H
MOV TH1,#0faH
MOV SCON,#050H
SETB TR1
START: MOV A,#'M'
ACALL F1
MOV A,#'e'
ACALL F1
MOV A,#'s'
ACALL F1
MOV A,#'s'
ACALL F1
MOV A,#'a'
ACALL F1
MOV A,#'g'
ACALL F1
MOV A,#'e' 
ACALL F1
SJMP START

F1: MOV SBUF,A
HERE:JNB TI,HERE
CLR TI
RET

Check if 5AH is located is located in any one of the locations.If yes load acc. by 5AH.

START: MOV R0,#5FH
 MOV R7,#10H
 COMPIT: CJNE @R0,#5AH,NEXT
 MOV A,#5AH
 SJMP FOUND
NEXT: DEC R0
DJNZ R7,COMPIT
NOMATCH : MOV A,#00H
FOUND : SJMP FOUND

Copy a block of 20bytes of data from 60h to 73h to the location starting from 40h.

START: MOV R0,#60H
 MOV R1,#40H
 MOV R7,#14H
COPYIT: MOV A,@R0
 MOV @R1,A
 INC R0
 INC R1
 DJNZ R7,COPYIT
 OVER: SJMP OVER

Program to shift a block of 8 bytes data,from 50h to 57h,1 byte up data is available from 51H to 58H

START: MOV R0,#57H
 MOV R1,#58H
 MOV R7,#08H
 SHIFT: MOV A,@R0
 MOV @R1,A
 DEC R0
 DEC R1
 DJNZ R7,SHIFT
 OVER :SJMP OVER

Program to display the message in 8051

ORG 0000
MOV DPTR,#MY_DATA
MOV R0,#50H
MOV R2,#5H
REPEAT : CLR A
MOVC A,@A+DPTR
MOV @R0,A
INC DPTR
INC R0 
DJNZ R2,REPEAT
HERE :SJMP HERE
ORG 240H
 MY_DATA : DB " HELLO"
END

Program to perform factorial of a number (8051)

MOV DPTR,#1000H
MOVX A,@DPTR
MOV R1,A
MOV A,#01H
LOOP: MOV B,R1
MUL AB
INC DPTR
DJNZ R1,LOOP
END

Program to perform 16 bit BCD addition in 8051

MOV DPTR,#2080H
MOV A,#20H
MOV B ,#10H
ADDC A,DPL
DA A  
MOV A,B
DA A
ADDC A,DPH
MOV B,A
DA A
MOV A,DPL
END