First of all I thank all to suggestions about the problem.
I think one has a right to download any evaluation software to try it and have an idea about it before to buy it. May I do not explain the problem in detail because I am not good in English language. We did used this sw in our technical school and if you look around the package you can find an assembled problem name (DEBUGIOH.ASM) the KCS themselves put this in package and so they encouraging you to do your own debugger. Any one can put this in EPROM and build a target system or debugger.

In school I asked to build a project some kind of debugger to cominucate with target system. I am not interested in how KSC have made the sw or debugger and I am not owning the system51 sw only thing was a little hardware problem.

The purpose of this project was an experimental method no more.
Every one has right to search any knowledge and research by them self or by help of others.

Hamid