rs485.h

在DOS环境下

#if !defined( _RS485_H )
#define _RS485_H

#define	COM1	0
#define	COM2	1
#define	COM3	2
#define	COM4	3

int InitUART( int PortNum, int BaudIdx );
int InstallISR( int PortNum );
int UninstallISR( int PortNum );

// return =  0: ok
//        = -1: output buffer full
int  PutOutputData( char abyte );
void StartSend( );

// return = -1: no data available
int  GetInputData( );

#endif