察举制的利弊:很难的问题?

来源:百度文库 编辑:查人人中国名人网 时间:2024/05/06 10:53:54
谁可以给我说说8259的中断程序
STACK SEGMENT STACK
DB 200 DUP(0)
STACK ENDS
C8259 EQU 20H
CODE SEGMENT 'CODE'
MAIN PROC FAR
ASSUME CS:CODE,SS:STACK
START: XOR AX,AX
MOV DS,AX
LEA AX,IRQ0
MOV DS:20H,AX
MOV AX,CS
MOV DS:22H,AX
MOV DX,C8259
MOV AL,00010011B
OUT DX,AL
INC DX
MOV AL,00001000B
OUT DX,AL
MOV AL,00001101B
OUT DX,AL
MOV AL,11111110B
OUT DX,AL
MOV AL,20H
OUT 20H,AL
MOV BL,'a'
MOV AL,BL
MOV AH,1
INT 14H
STI
JMP $
IRQ0: CLI
INC BL
CMP BL,'{'
JNZ NEXT
MOV AH,4CH
INT 21H
NEXT: MOV AL,BL ; EOI
MOV AH,1
INT 14H
MOV AL,20H
OUT 20H,AL
STI
IRET
MAIN ENDP
CODE ENDS
END START

这个谁能回答出来真厉害