hi to all i am using keil V3 evolution version still i am working on the AT89s52 but now i am thinking to switch to some new microcontroller which having more than 256 Bytes On-chip RAM, AT89c51RC having 512 Bytes On-chip RAM which is enough for me and but i did not got the include header file for AT89c51RC i search all INC-->ATMEL folder but did not found its header file AT89c51RC2.h is there AT89c51Rb2.h is also present can any one help me in this is any one microcontroller having more than 512 Bytes On-chip RAM not XRAM help me