Hi All LCD is connected to 89C51RD2,its control lines RS,R/W & E are connected to p1.1,p1.2 & p1.3 rspv. Decoder is used for enabling SRAM,RTC,PPI. Rest all port lines of microcontroller are occupied. i require two more port lines now, but since there are none,i am trying to enable LCD from decoder using memory map. have any body tried this ? if yes what are things to be taken care ? u can forward supporting document related to this at rana_naresh@hotmail.com Regards Naresh