Some time back i got a frequency counter from a fellow ham. On switching ON it showed his callsign.I decided to change the program in the microcontroller so that it shows my call sign during startup. I inserted the PIC to the programmer which is connected to the printer port of my computer. I downloaded the hex file from the microcontroller. Using a dis-assembler software i disassembled the hex code to the corresponding PIC instructions. I found the data memory of the PIC was used for storing words like 'FREQUENCY' , MHz etc. No trace of his call sign! Then i went to the program memory and found the ASCII values of his call sign in a series of instructions. I replaced those ASCII values with the ASCII values of my callsign.I put the PIC back in the counter and found it showing my call sign during startup. Mission accomplished .........