我对汇编编程非常陌生 我发现这段代码可以检测数字是否为质数。我现在想知道如何获取用户输入的NUM值。
我在https://github.com/kingspp/8086-MicroProcessor/blob/master/Prime-Check.asm找到了代码
如果有人向我解释如何使用8086寄存器来获取输入，我将不胜感激。
我看了几遍
;NUM is assigned to the Number to be checked
;AL is used as the default no
;BL is used as Dividing Variable. It is Incremented in each loop
;BH is used to know the number of variables which can divide the Number. BH>02, The number is not prime
;BL is made to run x number of times, where x is the given number.
; Declaration Part
.MODEL SMALL
.DATA
NM1 DB "FirstName LastName$"
NM2 DB "FirstName LastName$"
MSG DB "It is Prime$"
NMSG DB "It is not Prime$"
NUM DB 27H ;Enter the required no here
.CODE
START:
MOV AX,@DATA
MOV DS,AX
MOV AL,NUM
MOV BL,02H ; The Dividing starts from 2, Hence BH is compare to 02H
MOV DX,0000H ; To avoid Divide overflow error
MOV AH,00H ; To avoid Divide overflow error
;Loop to check for Prime No
L1:DIV BL
CMP AH,00H ; Remainder is compared with 00H (AH)
JNE NEXT
INC BH ; BH is incremented if the Number is divisible by current value of BL
NEXT:CMP BH,02H ; If BH > 02H, There is no need to proceed, It is not a Prime
JE FALSE ; The no is not a Prime No
INC BL ; Increment BL
MOV AX,0000H ; To avoid Divide overflow error
MOV DX,0000H ; To avoid Divide overflow error
MOV AL,NUM ; Move the Default no to AL
CMP BL,NUM ; Run the loop until BL matches Number. I.e, Run loop x no of times, where x is the Number given
JNE L1 ; Jump to check again with incremented value of BL
;To display The given no is a Prime No
TRUE:
LEA DX,NM1
LEA DX,NM2
LEA DX,MSG
MOV AH,09H ; Used to print a string
INT 21H
JMP EXIT
;To display The given no is not a Prime No
FALSE:
LEA DX,NM1
LEA DX,NM2
LEA DX,NMSG
MOV AH,09H ; Used to print a string
INT 21H
EXIT:
MOV AH,4CH
INT 21H
END START