第1个回答 2008-11-13
呵呵~~我们是同行啊~~~也许是对的吧~~顶~~
顶~~~
顶~~~~MOV AX,FLAGS
AND AX,1111110111111111B ;关中断
MOV FLAGS,AX
MOV AL,00110110B ;假设定时器0设为方式3
OUT 43H,AL
MOV AL,XXH ;
OUT 40H,AL
MOV AL,XXH
OUT 40H,AL ;定时器0初值
MOV AL,01110110B ;假设定时器1设为方式3
OUT 43H,AL
MOV AL,XXH ;
OUT 41H,AL
MOV AL,XXH
OUT 41H,AL ;定时器1初值
MOV AH,35H
MOV AL,0AH
INT 21H
PUSH ES ;保存原向量
PUSH BX
PUSH DS ;借用DS和DX作中断入口,暂时保存原值
PUSH DX
MOV DS,XXH ;新中断向量段地址
MOV DX,XXH ;新中断向量偏移量
MOV AH,25H
MOV AL,0AH
INT 21H
POP DX
POP DS
IN AL,21H
MOV SAV_IR,AL ;保存原8259设置(必须事先在数据段中为SAV_IR开辟一个字节的空间)
OR AL,00000100B ;开IR2
OUT 21H,AL
MOV AX,FLAGS
OR AX,0000001000000000B ;开中断
MOV FLAGS,AX
WAIT1:
JMP WAIT1
2.
MESSAGE DB 'THIS IS A 8259A INTERRUPT$'
SAV_IR DB 0
MOV AH,9
MOV DX,SEG MESSAGE
MOV DS,DX
MOV DX,OFFSET MESSAGE
INT 21H
MOV AX,FLAGS
AND AX,1111110111111111B ;关中断
MOV FLAGS,AX
PUSH DS ;借用DS和DX作中断入口,暂时保存原值
PUSH DX
MOV DS,ES
MOV DX,BX ;原0AH中断向量值
MOV AH,25H
MOV AL,0AH
INT 21H
POP DX
POP DS
MOV AL,SAV_IR ;读回8259原设置值
OUT 21H,AL
MOV AX,FLAGS
OR AX,0000001000000000B ;开中断
MOV FLAGS,AX
IRET
第2个回答 2008-11-12
1.
MOV AX,FLAGS
AND AX,1111110111111111B ;关中断
MOV FLAGS,AX
MOV AL,00110110B ;假设定时器0设为方式3
OUT 43H,AL
MOV AL,XXH ;
OUT 40H,AL
MOV AL,XXH
OUT 40H,AL ;定时器0初值
MOV AL,01110110B ;假设定时器1设为方式3
OUT 43H,AL
MOV AL,XXH ;
OUT 41H,AL
MOV AL,XXH
OUT 41H,AL ;定时器1初值
MOV AH,35H
MOV AL,0AH
INT 21H
PUSH ES ;保存原向量
PUSH BX
PUSH DS ;借用DS和DX作中断入口,暂时保存原值
PUSH DX
MOV DS,XXH ;新中断向量段地址
MOV DX,XXH ;新中断向量偏移量
MOV AH,25H
MOV AL,0AH
INT 21H
POP DX
POP DS
IN AL,21H
MOV SAV_IR,AL ;保存原8259设置(必须事先在数据段中为SAV_IR开辟一个字节的空间)
OR AL,00000100B ;开IR2
OUT 21H,AL
MOV AX,FLAGS
OR AX,0000001000000000B ;开中断
MOV FLAGS,AX
WAIT1:
JMP WAIT1
2.
MESSAGE DB 'THIS IS A 8259A INTERRUPT$'
SAV_IR DB 0
MOV AH,9
MOV DX,SEG MESSAGE
MOV DS,DX
MOV DX,OFFSET MESSAGE
INT 21H
MOV AX,FLAGS
AND AX,1111110111111111B ;关中断
MOV FLAGS,AX
PUSH DS ;借用DS和DX作中断入口,暂时保存原值
PUSH DX
MOV DS,ES
MOV DX,BX ;原0AH中断向量值
MOV AH,25H
MOV AL,0AH
INT 21H
POP DX
POP DS
MOV AL,SAV_IR ;读回8259原设置值
OUT 21H,AL
MOV AX,FLAGS
OR AX,0000001000000000B ;开中断
MOV FLAGS,AX
IRET