Hello Aratti,
thanks a lot for your help,
i realize that i should not have to use an external eeprom. the pic 16f877a containes an 8k bytes, a lot of space to be written on. the problem now is how to write data on these pages (FLASH MEMORY), use DATA , EEPROM or other PBP commands; or copy the code from data sheet?

but,,, not sure i understand all.