6-1.asm

来自「微机课的全部实验」· 汇编 代码 · 共 47 行

      INTA00  EQU       20H         ;偶地址
      INTA01  EQU       21H         ;奇地址
        DATA  SEGMENT
        MESS  DB        'THIS IS THE 8259 INTRUPT !',0AH,0DH,'$'
        DATA  ENDS
        CODE  SEGMENT
              ASSUME    CS:CODE,DS:DATA
      START:  MOV       AX,DATA
              MOV       DS,AX
              MOV       DX,OFFSET INT_PROC
              MOV       AX,SEG    INT_PROC
              MOV       DS,AX
              MOV       AL,0FH
              MOV       AH,25H
              INT       21H
              CLI
              MOV       DX,INTA01
              IN        AL,DX
              AND       AL,7FH      ;开中断
              OUT       INTA01,AL
              MOV       BX,10
              STI
         LL:  JMP       LL
   INT_PROC:
              MOV       AX,DATA
              MOV       DS,AX
              MOV       DX,OFFSET MESS
              MOV       AH,09H
              INT       21H
              MOV       DX,INTA00
              MOV       AL,20H
              OUT       DX,AL
              DEC       BX
              JNZ       NEXT
              MOV       DX,INTA01
              IN        AL,DX
              OR        AL,80H
              OUT       DX,AL
              STI
              MOV       AH,4CH
              INT       21H
       NEXT:  IRET
        CODE  ENDS
              END       START