Hi Harnam,
It seems that you have the circuit diagram and and every thing else needed to construct the project, execpt the eprom inside the uC!
Just assuming that, let me tell you that; you just have to take care of the EA pin of the uC chip. and a little modification to the the Circuit diagram.
Just put an EPROM programmed with the code and interface it to the uC as requred.
Let me clarify, I don't know which project you are discussing about, and i assume that the pins required to interface a Eprom outside the uc are free, as it is a simple project.

Goodluck
Biswajit Gupta