我现在需要做的用Borland c3.1开发DOS下的软件,我想知道,在这样的环境下,如何通过RS232串口进行通讯??在线等待!!!!

[wardwind]

我现在需要做的用Borland c3.1开发DOS下的软件,我想知道,在这样的环境下,如何通过RS232串口进行通讯??
我听说可以用BIOSCOM函数也可以直接用OUTPUT函数,请问该如何使用?哪有这方面的实例?????

[HellotoYou]

别人的一个小例子：
#include <dos.h>
#include <stdio.h>
#include <conio.h>

#define PORT1 0x2E8 /* Port Address Goes Here */
/* Defines Serial Ports Base Address */
/* COM1 0x3F8 */
/* COM2 0x2F8 */
/* COM3 0x3E8 */
/* COM4 0x2E8 */

#define INTVECT 0x0B /* Com Port's IRQ here */
/* (Must also change PIC setting) */

int bufferin = 0;
int bufferout = 0;
char ch;
char buffer[1025];
void interrupt (*oldport1isr)();

void interrupt PORT1INT() /* Interrupt Service Routine (ISR) for PORT1 */
{
int c;
do {
c = inportb(PORT1 + 5);
if (c & 1) {
buffer[bufferin] = inportb(PORT1);
bufferin++;
if (bufferin == 1024)
bufferin = 0;
}
}while (c & 1);

outportb(0x20,0x20);
}

void main(void)
{
int c;

outportb(PORT1 + 1 , 0); /* Turn off interrupts - Port1 */
oldport1isr = getvect(INTVECT); /* Save old Interrupt Vector for */
/* later recovery */
setvect(INTVECT, PORT1INT); /* Set Interrupt Vector Entry */
/* COM1 - 0x0C */
/* COM2 - 0x0B */
/* COM3 - 0x0C */
/* COM4 - 0x0B */
/* PORT 1 - Communication Settings */

outportb(PORT1 + 3 , 0x80); /* SET DLAB ON */
outportb(PORT1 + 0 , 0x03); /* Set Baud rate - Divisor Latch Low Byte */
/* Default 0x03 = 38,400 BPS */
/* 0x01 = 115,200 BPS */
/* 0x02 = 56,700 BPS */
/* 0x06 = 19,200 BPS */
/* 0x0C = 9,600 BPS */
/* 0x18 = 4,800 BPS */
/* 0x30 = 2,400 BPS */
outportb(PORT1 + 1 , 0x00); /* Set Baud rate - Divisor Latch High Byte */
outportb(PORT1 + 3 , 0x03); /* 8 Bits, No Parity, 1 Stop Bit */
outportb(PORT1 + 2 , 0xC7); /* FIFO Control Register */Interfacing the Serial / RS232 Port V5.0 http://www.senet.com.au/~cpeacock
outportb(PORT1 + 4 , 0x0B); /* Turn on DTR, RTS, and OUT2 */
outportb(0x21,(inportb(0x21) & 0xF7)); /* Set Programmable Interrupt */
/* Controller */
/* COM1 (IRQ4) - 0xEF */
/* COM2 (IRQ3) - 0xF7 */
/* COM3 (IRQ4) - 0xEF */
/* COM4 (IRQ3) - 0xF7 */
outportb(PORT1 + 1 , 0x01); /* Interrupt when data received */
printf("\nSample Comm's Program. Press ESC to quit \n");
do {
if (bufferin != bufferout){
ch = buffer[bufferout];
bufferout++;
if (bufferout == 1024) bufferout = 0;
printf("%c",ch);
}
if (kbhit()){
c = getch();
outportb(PORT1, c);
}
} while(c !=27);

outportb(PORT1 + 1 , 0); /* Turn off interrupts - Port1 */
outportb(0x21,(inportb(0x21) | 0x08)); /* MASK IRQ using PIC */
/* COM1 (IRQ4) - 0x10 */
/* COM2 (IRQ3) - 0x08 */
/* COM3 (IRQ4) - 0x10 */
/* COM4 (IRQ3) - 0x08 */
setvect(INTVECT, oldport1isr); /* Restore old interrupt vector */
}

[own]

BIOSCOM函数用起来简单，他已经屏蔽了对寄存器的操作，output函数则是直接对川口芯片的寄存器操作，这有利于对川口通信的理解

[Thie]

《C高级程序设计》

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清华大学出版社