PROGRAMMING IN 8086

Fact = N * (N–1)*….2*1  (all are unsigned Word variable)


 TITLE factorial 
;TO COMPUTE
;factorial N <= 8
;----------------------------------------------------------------
     .MODEL SMALL
     .STACK 64
     .DATA
     VAR_N DW 9 
     VAR_FACT DW 1
;----------------------------------------------------------------
     .CODE
MAIN PROC FAR
     MOV AX,@DATA
     MOV DS,AX
     MOV AX,VAR_N 
     MOV DX,01
     CMP AX,00h
     JE SPECIAL
     MOV CX,AX
     MOV BX,AX
     DEC BX      
     DEC CX  
     JZ SPECIAL
     LOOP: MUL BX
           DEC BX 
           DEC CX
           JNZ LOOP         
     MOV DX,AX
     SPECIAL:MOV VAR_FACT,DX
     MOV AX,4C00H
     INT 21H
MAIN ENDP
     END MAIN
    

ROGRAMMING IN 8086

1. Write an assembly program that converts a number in the word variable D, 0 <= D <= 15 to an ASCII character in the byte variable HEXD which is its hex value. For instance, if D = 3 then HEXD = ‘3’ and if D = 14 then HEXD = ‘E’.

TITLE  word variable to ASCII character
;----------------------------------------------------------------
     .MODEL SMALL
     .STACK 64
     .DATA
     ;ACODE   DB '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'
     ACODE DB '0123456789ABCDEF'
     VALUE   DW 7  
     INDEX   DB 0
     HEXVAL  DB '?'  
;----------------------------------------------------------------
     .CODE
MAIN PROC FAR
     MOV AX,@DATA
     MOV DS,AX
     MOV ES,AX
     MOV CX,15
     LOOP:
            MOV AX,CX
            CMP AX,VALUE
            JE GOT
            INC INDEX
            DEC CX
            JNZ LOOP
     GOT:MOV AL,15
     SUB AL,INDEX
     MOV INDEX,AL
     MOV CL,INDEX
     INC CL
     LEA SI,ACODE
     LOOP1:MOV AL,[SI]
           MOV HEXVAL,AL
          INC SI
          DEC CL
          JNZ LOOP1
     MOV AX,4C00H
     INT 21H
MAIN ENDP
     END MAIN  ;END MAIN PROCEDURE
    

Programming in 8086

1. Write a program to find out the number of positive and negative numbers from a given array of 10 16-bit numbers

TITLE POSITIVE NEGATIVE
;TO COMPUTE THE NUMBER OF
;POSITIVE AND NEGATIVE NUMBERS
;----------------------------------------------------------------
     .MODEL SMALL
     .STACK 64
     .DATA
     VAR_POS DW 00
     VAR_NEG DW 00  
     ARRAY DW 2,-3,4,5,6,-7,8,9,-2,3 ; input to the program
;----------------------------------------------------------------
     .CODE
MAIN PROC FAR
     MOV AX,@DATA  ; SET ADDRESS OF DATA SEGMENT IN DS
     MOV DS,AX
     MOV CX,10d  ; LOOP COUNTER
     MOV SI,OFFSET ARRAY ; LOADING BX WITH OFFSET
     LOOP:      
         CLC
         XOR AX,AX
         MOV AX,[SI] ; MOVING THE POINTED DATA
         RCL AX,1    ; ROTATE TO CHECK FOR MSB
         JC NEGA
         INC VAR_POS ; IF CARRY FLAG IS RESET (0), INCREASE VAR_POS
         JMP NEXT
         NEGA:
             INC VAR_NEG ; IF CARRY FLAG IS SET (1), INCREASE VAR_NEG
         NEXT:
             INC SI   ;TO FETCH THE
             INC SI   ; NEXT WORD
             DEC CX   ; LOOP UNTIL DATA ARE PROCESSED
         JNZ LOOP                                                                    
     MOV AX,4C00H
     INT 21H
MAIN ENDP
     END MAIN  ;END MAIN PROCEDURE