Question

socket php怎么实现客户端与客户端通信

Answer 1

8259A共有三个工作命令字,但下例中只用过OCW1.
| OCW1将所有的中断都屏蔽掉, OCW2&OCW3也就没什么意义了.
| ** ICW stands for Initialization Command Word;
| OCW for Operation Command Word.
1. mov al,#0x11
out #0x20,al
.word 0x00eb,0x00eb | jmp +2, jmp +2
2. out #0xA0,al | and to 8259A-2
.word 0x00eb,0x00eb
3. mov al,#0x20 | 向主8259A写入ICW2.
out #0x21,al | 硬件中断入口地址0x20, 并由ICW1

| 得知中断向量长度 = 8 bytes.
.word 0x00eb,0x00eb
4. mov al,#0x28 | start of hardware int's 2 (0x28)
out #0xA1,al | 第二块8259A的中断入口是0x28.
.word 0x00eb,0x00eb
5. mov al,#0x04 | 8259-1 is master
out #0x21,al | Interrupt Request 2有级联处理.

.word 0x00eb,0x00eb
mov al,#0x02 | 8259-2 is slave
out #0xA1,al | 于上面对应,告诉大家我就是IR2对应
| 级联处理器.
.word 0x00eb,0x00eb
6. mov al,#0x01 | 8086 mode for both
out #0x21,al
.word 0x00eb,0x00eb
out #0xA1,al