a10-2.asm

汇编语言的设计

STACK SEGMENT STACK
	DW 64 DUP(?)
STACK ENDS

CODE SEGMENT
	ASSUME CS:CODE

START:	CLI
	MOV AL,0A6H
	OUT  63H,AL
	MOV AL,05H
	OUT 63H,AL
        PUSH DS
	MOV AX,0000H
	MOV DS,AX
	MOV AX,OFFSET IRQ7
	ADD AX,2000H
	MOV SI,003CH
	MOV [SI],AX
	MOV AX,0000H
	MOV SI,003EH
	MOV [SI],AX
	POP DS
	IN AL,21H
	AND AL,7FH
	OUT 21H,AL
A1:	STI
	HLT
	JMP A1
IRQ7:	IN AL,61H
	OUT 60H,AL
	MOV AL,20H
	OUT 20H,AL
	IRET
CODE ENDS
     END START