Hi Martin,

There are tutorials here explaining the 8051 and its peripherals including UART, timers and interrupts.

There a code library here too. Look to the left.

You can also find apnotes and sample code at most chip vendors...I usually get mine from Atmel, Dallas or Philips.

A little searching will get you the code you want.

Then do a search here and you'll find many threads discussing serial communications.

Dennis