simualtors for real time appliaction

hello friend , can anybody telll me the simulator i can use for 8051 microcontroller . i want a simulator which can do real time application . i can design the circuit and then post my code in that and check for the out put . i got a software proteus professional but its a demo version i can't save the circuits .. the circuits are saved in .dsn extension . can u tell me a software will perform the above task but we can save the circuit ... if u have link send me ...to my mail [email protected] ..

please stop posting the same topics again and again. i am closing the other topic. if someone want to reply he/she can reply here.