n!.txt

这是一个在汇编语言中如何实现阶乘的小程序

DATA        SEGMENT

RSULT      DW ? 

N      DB 5

DATA        ENDS 

STAK        SEGMENT STACK  

         DW 1024 DUP(?) 

STAK        ENDS 

CODE        SEGMENT 

         ASSUME CS:CODE, SS:STAK, DS:DATA   

START:      MOV AX, DATA 

         MOV DS, AX

         XOR DX, DX

         XOR AH, AH

         MOV AL, N

         CALL FCTRIL  

         MOV RSULT, DX

         MOV AH, 4CH

         INT 21H

FCTRIL     PROC NEAR  

         CMP AL, 0

         JNZ NXT 

         MOV DL, 1 

         RET 

NXT:         PUSH AX

         DEC AL

         CALL FCTRIL

         POP CX

         MOV AL, DL 

         MUL CL 

         MOV DX, AX 

         RET 

FCTRIL     ENDP 

CODE        ENDS 

         END START