Dear all, In our project we are using P87c51mc2 micro controller and a 512k bytes flash. Our requirement is, we don't want put any single instruction below 96k(onchip rom of the controller).Any code including startup and initialization code must be put after 96k. We have gone through some documents posted on keil website. But our case is some what different. It should start at the address beyond 64k(i.e,beyond 96k, including reset vector and interrupt vectors). I have tried to modify the startup code : CSEG AT 0 to some other value that is greater than 64k. But the compiler is not accepting this, it is giving the error: "INVALID ABSOLUTE BASE/OFFS VALUE" Even the case of interrupt vector addresses is also same. Please give me a solution to come out of this problem. Thanks in advance, Srilatha.