
/*
 *   INT14
 *   MS-DOS sarjaportin i/o-rutiineja Microsoft C:ll{
 *
 *   Tapani Lindgren 15-JUNE-1986
 *
 */

#include <dos.h>

int getport(portno)
int   portno;   /* io port number */
/* get a character from input port - return EOF if no character available */
union REGS regs;
{
      regs.x.dx = portno;
      regs.h.ah = 3;   /* status call */
      int86(0x14, &regs, &regs);
      if (regs.h.ah & 1) {   /* data ready? */
         regs.h.ah = 2;      /* receive char */
         int86(0x14, &regs, &regs);
         return(regs.h.al);
      } else
         return(EOF);      /* no char available */
}   /* getport */


int putport(portno,c)
int   portno;
/* put a character to output port - return 1 if succeeded, 0 if port not ready */
int   c;
union REGS regs;
{
      regs.x.dx = portno;
      regs.h.ah = 3;   /* status call */
      int86(0x14, &regs, &regs);
      if (regs.h.ah & 0x20) {   /* transmit buffer empty */
         regs.h.ah = 1;      /* transmit char */
         int86(0x14, &regs, &regs);
         return(1);
      } else
         return(0);
}   /* putport */



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