To use the 8051 microcontroller, you definitely need to program it first for the intended purpose. What does that mean actually? The 8051 itself is just a piece of hardware capable of doing nothing at all. It is actually the software that makes it intelligent and gives some meaning to its life. The software defines the purpose of the 8051 or solution to a particular problem. Now how to program it? It's very simple to understand.
UPDATE: Visit this link for a newer and updated version of this post - with detailed instructions.
UPDATE: Visit this link for a newer and updated version of this post - with detailed instructions.