Hi all,
thanks for all your responses, the chip i am using is the 89c51cc01. it has the enhanced UART you talk about, which is what I am using. I got the SADDR and SADEN info from the datasheet, not from looking at code. I am still a bit unsure how it works...

from one post above you guys seemed to suggest using the 9-bit mode and if the ninth bit is set (by me in code?) then the micro knows this is an address? the next byte it receives is then the data for it? basically what i am trying to do is send a data string out of the master 8051 and then between 2-16 receivers will listen in. They will all have an individual address that could be written to the SADDR register if necessary. the string will be sent in the order.
address 1
data for that address
address 2
data for that address
etc

hope you can help me out. I appreciate your help so far