And to add....assembly language software can feel free to use the GF0 and GF1 bits as convenient bit level variables in your program. Use of GF0 and GF1 will be somewhat useless in C programs because I have found that some C library functions use these bits. See these threads for more details...

http://www.8052.com/forum/read.phtml?id=50530

http://www.8052.com/forum/read.phtml?id=53072

Michael Karas