Shahzad,

First of all, i would recommend you to prpoerly specify your problem. For example, you wrote:
i downloaded a simple LED blinking program from net

Then you said you write LED instead of LCD. So it was an LCD program. Am I right??

I can't understand a blinking LCD program, whats blinking on LCD? A blinking LED makes more sense to me.

Port pins of 89C2051 and 89C51 are same, only difference is that 89C2051 doesn't have all four ports. Secondly, P1.0 and P1.1 on 89C2051 require pull-up resistor just as port 0 requires pull-up in 89C51.There might be differences in driving capibility, but software fuctionality is same. I think 89C2051 has more driving capability, at least Atmel claims that!

Remember these micros are CMOS devices and touching the pins may be fatal to these. You might have thousands volts of static electricity on your hands. If you touch the pins of CMOS devices while they are running, a phenomena known as Latch up might occur.

Try a search for Latch up problems in CMOS, and you will find good info.

I want to know if any program(other than yours) works on your 89C51 board? If yes, then you are not connecting the LCD to same port pins as in 89C2051 board (which works as you said).

IA