rs232 protocol

Look at the datasheet, it goes a good job of explaining how it works: http://datasheets.maxim-ic.com/en/ds/MAX220-MAX249.pdf

if i read i can understand what the point i post here?

Pages 14 through 16 of the datasheet detail the operation of the chip. What don't you understand? Do you have a basic understanding of electronics and RS-232 communications?

if i know i wont be here asking you dude