#include <reg51.h>
#define uchar unsigned char
#define uint unsigned int
sbit pos1=P0^0;
sbit neg1=P0^1;
sbit add=P0^2;
sbit minus=P0^3;
uchar code motopos[8]={0x02,0x06,0x04,0x0c,0x08,0x09,0x01,0x03};
uchar code motoneg[8]={0x0b,0x09,0x0d,0x0c,0x0e,0x06,0x07,0x03};
uchar s=200;
uchar m=0;uchar n=0;
void delay(uchar x)
{
  uchar i,j;
  for(i=0;i<x;i++)
    for(j=0;j<120;j++);
}
void pos()
{
  //uchar m;
  //for(m=0;m<8;m++)
    //{
	  P1=motopos[m];
	  delay(s);
	  m++;
	  if (m==8) m=0;
	//}
}
void neg()
{
  
 // for(n=0;n<8;n++)
    //{
	  P1=motoneg[n];
	  delay(s);
	  n++;
	  if (n==8) n=0;
	//}
}
void main ()
{
  while(1)
  {
    if (add==0)
	  {
	    delay(10);
		if(add==0)
		{
		s=s-10;
		if (s<=100) s=100;
		}		
	  }
	if (minus==0)
	  {
	    delay(10);
		if(minus==0)
		{
		s=s+10;;
		if (s>=200) s=200;
		}		
	  }
	if (pos1==0)
	  {
	    delay(10);
		if(pos1==0) pos();
		while (pos1==0);				
	  }
	if (neg1==0)
	  {
	    delay(10);
		if(neg1==0) neg();
		while (neg1==0);	
	  }
  }
}