;MULTIPLICATION OF DUNAMICALLY ANY SINGLE, DOUBLE, TRIPLE DIGIT NUMBERS AND DISPLAY USING LOOP AND DISPLAY SUM IN ASSEMBLY
ORG 100H
.MODEL SMALL
.STACK 100H
.DATA    
RANGE DB 13,10, 'ENTER RANGE: $'
R DW ?
EN DB 13,10,'ENTER A NUMBER: $'
N DW ?
UN DB 13,10, 'MULTIPLICATION = $'  
MULT DW 1

.CODE
MAIN PROC
    MOV AX,@DATA
    MOV DS,AX
    
    MOV DX,OFFSET RANGE
    MOV AH,9
    INT 21H
    
    MOV AH,1 ;INPUT STORES IN AL
    INT 21H
    MOV AH,0
    MOV R,AX
    SUB R,48 
    
    MOV CX,R  
    
    L:
    PUSH CX
    MOV DX,OFFSET EN
    MOV AH,9 ;FOR PRINTING STRING
    INT 21H
    
    ;INPUT CODE STARTS HERE
    MOV N,0      ;N = 0          
    MOV BL,10    ;BL = 10
    INPUT:       ;LOOP LABEL
    MOV AH,1     ;INPUT A CHARACTER => STORES IN AL
    INT 21H      ;INTERUPT FOR TEXT
    CMP AL,13    ;COMPARE INPUT WITH ENTER KEY
    JE NEXT      ;IF JUMP EQUAL TO THEN ITS JUMP ON LABEL
    SUB AL,30H   ;SUB AL = AL - 48 = AL - 30H
    MOV AH,0     ;AH = 0
    MOV CX,AX    ;CX = AX
    MOV AX,N     ;AX = N
    MUL BL       ;MULTIPLY => AX = AX * BL
    ADD AX,CX    ;ADD => AX = AX + CX 
    MOV N,AX     ;N = AX
    JMP INPUT
    ;INPUT CODE ENDS HERE
    
    NEXT:
    MOV AX,N    ;AX = N 
    MOV BX,MULT ;BX = MULT
    MUL BX      ;AX = AX * BX
    MOV MULT,AX ;MULT = AX
    POP CX
    LOOP L
    
    LEA DX,UN ;LOAD EFFECTIVE ADDRESS
    MOV AH,9
    INT 21H
    
    ;OUTPUT CODE STARTS HERE
    MOV AX,MULT  ;AX = SUM = 25
    MOV DX,0  ;DX = 0
    MOV BX,10 ;BX = 10
    MOV CX,0  ;CX = 0 => COUNTER REGISTER
    L1:
    DIV BX    ;DIVIDE => AX = AX / BX
    ;IN CASE OF 8 BIT REGISTER => AL = QUOTIENT, AH = REMAINDER
    ;IN CASE OF 16 BIT REGISTER => AX = QUOTIENT, DX = REMAINDER
                                  ;AX = 2       , DX = 5
    PUSH DX   ;5 SAVE IN STACK
    MOV DX,0  ;DX = 0
    MOV AH,0  ;AX AH = 00000000, AL = QUOTIENT
    INC CX    ;CX = CX + 1
    CMP AX,0  ;(2 == 0)
    JNE L1    ;JUMP NOT EQUAL => AX != 0
    MOV AH,2  ;OUTPUT/PRINT A SINGLE CHARACTER
    L2:
    POP DX    ;FIRST TIME POP 2 AND SECOND TIME POP 5 = 25
    ADD DX,48
    INT 21H
    LOOP L2
    ;OUTPUT CODE ENDS HERE
    
    RET 
    
    MAIN ENDP
    END MAINP