Well sir i have read the PDF which was called "The Bibile" of MCu by Sir Erik Muland, although it was great document and it was also very help full but after reading i have tried to design the system in which there are many slaves connected with a Master (in this time PC's RS-232), but there was problem arised that how to send the 9th bit from computer ? (by using HyperTerminal) well although i know VB but there is no feature in also VB to set and reset the 9th bit to distinguish between the Data and Address...

well for the slaves i have used same program as it was given in "The Bibile" but only with some changing the naming constants...

in nutshell my first slave's address is
SADDER = 11110001
SADDEN = 11111010 (Same as in PDF)

so please could any one have idea how to communicate the Slaves through the PC's RS-232 (although i am also using the MAX232) for lavel conversion, i know that it is impossible to communicate without it) ....... (Looks like i am noob but not that much ;-) )