/***                LISTING 5                 ***/
/***                                          ***/
/***                  sin.c                   ***/
/*** **************************************** ***/
/***    INPUT A CHARACTER FROM SERIAL PORT    ***/
/*** **************************************** ***/
#include "serial.h"
#include <time.h>

extern int portbase;

int SerialIn()
  {
   int Char_Value;
   clock_t start, timeout;

   start = clock();

   while((inp(portbase + LSR) & RCVRDY) == 0)
    {
     timeout = clock();

     if((timeout-start) > 1)
      {
       return(-1);
      }
    }

  Char_Value = inp(portbase + RXR);
  return (Char_Value);
}