Dear Ijaz,

Thank you for your urgently reply.
Yes, I made my test board, just what this application needed.
The clock signs on the address and data pins of controller are the same like on a professional test board. (with oscilloscope)
My Code as simply as it can and perfectly working in a simulator. :)) (SW and HW too!)
That is why I don't anderstand it!
The RESET pulse is correct when I power it up.

Could you more explain that what does "EPROM must be correctly mapped in the external code memory space and every component should be functional" mean? (My english is weak)
And last I have a several OTP 8051, but I haven't a burner for it, but I built an EPROM burner, so this is the reason of why I'am playing with external EPROMs! :)) And I don't belive that I can't do this!

Thank You for your help.
Regard
Laszlo Nagy