#include <AT89X51.H>
unsigned char code table[]={0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71};
unsigned char temp;
unsigned char key;
unsigned char i,j;
unsigned char STH0;
unsigned char STL0;
unsigned int code tab[]={64021,64103,64260,64400,
64524,64580,64684,64777,
64820,64898,64968,65030,
65058,65110,65157,65178};

void main(void)
{
TMOD=0x01;
ET0=1;
EA=1;

while(1)
{
P3=0xff;
P3_4=0;
temp=P3;
temp=temp & 0x0f;
if (temp!=0x0f)
{
for(i=50;i>0;i--)
for(j=200;j>0;j--);
temp=P3;
temp=temp & 0x0f;
if (temp!=0x0f)
{
temp=P3;
temp=temp & 0x0f;
switch(temp)
{
case 0x0e:
key=0;
break;
case 0x0d:
key=1;
break;
case 0x0b:
key=2;
break;
case 0x07:
key=3;
break;
}
temp=P3;
P1_0=~P1_0;
P0=table[key];
STH0=tab[key]/256;
STL0=tab[key]%256;
TR0=1;
temp=temp & 0x0f;
while(temp!=0x0f)
{
temp=P3;
temp=temp & 0x0f;
}
TR0=0;
}
}

P3=0xff;
P3_5=0;
temp=P3;
temp=temp & 0x0f;
if (temp!=0x0f)
{
for(i=50;i>0;i--)
for(j=200;j>0;j--);
temp=P3;
temp=temp & 0x0f;
if (temp!=0x0f)
{
temp=P3;
temp=temp & 0x0f;
switch(temp)
{
case 0x0e:
key=4;
break;
case 0x0d:
key=5;
break;
case 0x0b:
key=6;
break;
case 0x07:
key=7;
break;
}
temp=P3;
P1_0=~P1_0;
P0=table[key];
STH0=tab[key]/256;
STL0=tab[key]%256;
TR0=1;
temp=temp & 0x0f;
while(temp!=0x0f)
{
temp=P3;
temp=temp & 0x0f;
}
TR0=0;
}
}

P3=0xff;
P3_6=0;
temp=P3;
temp=temp & 0x0f;
if (temp!=0x0f)
{
for(i=50;i>0;i--)
for(j=200;j>0;j--);
temp=P3;
temp=temp & 0x0f;
if (temp!=0x0f)
{
temp=P3;
temp=temp & 0x0f;
switch(temp)
{
case 0x0e:
key=8;
break;
case 0x0d:
key=9;
break;
case 0x0b:
key=10;
break;
case 0x07:
key=11;
break;
}
temp=P3;
P1_0=~P1_0;
P0=table[key];
STH0=tab[key]/256;
STL0=tab[key]%256;
TR0=1;
temp=temp & 0x0f;
while(temp!=0x0f)
{
temp=P3;
temp=temp & 0x0f;
}
TR0=0;
}
}

P3=0xff;
P3_7=0;
temp=P3;
temp=temp & 0x0f;
if (temp!=0x0f)
{
for(i=50;i>0;i--)
for(j=200;j>0;j--);
temp=P3;
temp=temp & 0x0f;
if (temp!=0x0f)
{
temp=P3;
temp=temp & 0x0f;
switch(temp)
{
case 0x0e:
key=12;
break;
case 0x0d:
key=13;
break;
case 0x0b:
key=14;
break;
case 0x07:
key=15;
break;
}
temp=P3;
P1_0=~P1_0;
P0=table[key];
STH0=tab[key]/256;
STL0=tab[key]%256;
TR0=1;
temp=temp & 0x0f;
while(temp!=0x0f)
{
temp=P3;
temp=temp & 0x0f;
}
TR0=0;
}
}
}
}

void t0(void) interrupt 1 using 0
{
TH0=STH0;
TL0=STL0;
P1_0=~P1_0;
}