(1) 用单脉冲发生器的输出作为中断请求信号使8259A产生中断,进入中断后显示一个字符串。(2) 中断请求通过8259的IRQ2端输入，中断源可以是片外8253定时器输出的脉冲，并把8253的OUTO和总线槽IR02连接好。
(3) 编写程序,要求每次主机响应外部中断IRQ2时,显示字符串“THIS IS A 8259A INTERRUPT!”(或其它串)，中断十次后，程序退出。
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SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001337s ]
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SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001637s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 572506 [ RunTime:0.189637s ]
