Thanks for the response.
That was my first querry .Here are the details.
I am using a derivative of 8051(89C2051).
It has only 15 i/o port.In that I am using
7 for the o/p(must).
Now I want to use 10 for the i/p.However the rate may be 1 second sequentially.
These i/p are from sensors which senses
5v D.C.and are directly connected to the i/p.
The codes should be minimum,as the size of the memory is only 2K (including my other
functions).