Program in Assembly for 8051 which show how you can use Asynchronize serial port to design multiprocessor system. in this program you can find 5 8051 CPUs that one of them is master with 4 slaves. the code can be copy everywhere you need to run multiprocessor system as source code.has passed the test.
File list:
Async Multi Process.jpg

MASTER.asm
SLAVE1.asm
SLAVE2.asm
SLAVE3.asm
SLAVE4.asm