自动查找打印口可用如下程序:
unsigned int far *fpb=(unsigned far * )0x00400008; /*在内存40:08H处单元中有打印地址*/
port_data=*fpb; /*取打印机数据口的地址*/
port_inp=*fpb+1; /*状态端口为数据口地址加1*/
port_ctrl=*fpb+2; /*控制端口为数据端口加2*/
unsigned int far *fpb=(unsigned far * )0x00400008; /*在内存40:08H处单元中有打印地址*/
port_data=*fpb; /*取打印机数据口的地址*/
port_inp=*fpb+1; /*状态端口为数据口地址加1*/
port_ctrl=*fpb+2; /*控制端口为数据端口加2*/
#include "conio.h"
int main(int argc, char* argv[])
{
unsigned int *fpb=(unsigned * )0x00400008; /*在内存40:08H处单元中有打印地址*/
long port_data=*fpb;
printf("%d\n",port_data);
return 0;
}output is 4 ?why?
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#include "conio.h"
int main(int argc, char* argv[])
{
unsigned int *fpb=(unsigned * )0x00400008; /*在内存40:08H处单元中有打印地址*/
long port_data=*fpb;
printf("%d\n",port_data);
return 0;
}output is 4 ?why?
would you like give me your Email?
my Email is [email protected]
thank you!!
又没有注意到这个far?一定要定义为远指针,在访问绝对内存地址的时候使用,因为这个地址在你的代码段之外。
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E:\seekparallel\seekparallel.cpp(15) : error C4226: nonstandard extension used : 'far' is an obsolete keyword
数字代表25芯插入式D-sub连接器上标出的引脚号。
计算机A<------>计算机B
pin 2 ---------- pin 15
pin 3 ---------- pin 13
pin 4 ---------- pin 12
pin 5 ---------- pin 10
pin 6 ---------- pin 11
pin10 ---------- pin 5
pin11 ---------- pin 6
pin12 ---------- pin 4
pin13 ---------- pin 3
pin15 ---------- pin 2
pin18到pin25,接地。pin1、pin14、pin16、pin17不连接。
至于程序么,你能看VB4编的程序么?我这里有一个例子,但是是用VB4写的。代码不多,但是贴在这里就太长了。给你发邮件如何?
ECP模式的连线与编程?