a11-2.asm

汇编语言的设计

STACK SEGMENT STACK
	DW 64 DUP(?)
STACK ENDS

CODE SEGMENT
	ASSUME CS:CODE

START:  PUSH DS
	MOV AX,0000H
	MOV DS,AX
	MOV AX,OFFSET IRQ0
	ADD AX,2000H
	MOV SI,0020H
	MOV [SI],AX
	MOV AX,0000H
	MOV SI,0022H
	MOV [SI],AX
	POP DS
	MOV AL,0FCH
	OUT 21H,AL
	MOV AL,15H
	OUT 43H,AL
	MOV AL,0FFH
	OUT 40H,AL
	MOV DL,30H
A1:	STI
	JMP A1
IRQ0:	MOV AH,01H
	MOV AL,DL
	CMP AL,3AH
	JNZ A2
	MOV AL,0DH
	INT 10H
	MOV AL,30H
A2:	INT 10H
	INC AX
	MOV DL,AL
	MOV AX,0120H
	INT 10H
	CALL DALLY
	MOV AL,20H
	OUT 20H,AL
	IRET
DALLY:	PUSH AX
	MOV CX,0100H
A3:	MOV AX,0560H
A4:	DEC AX
	JNZ A4
	LOOP A3
	POP AX
	RET
CODE ENDS
     END START