asynchronous communication

what are the advantages of asynchronous ?
and innigel's tut about rs232 'The signal itself is slightly unusual for computers, as rather than the normal 0V to 5V range, it uses +12V to -12V - this is done to improve reliability, and greatly increases the available range it can work over '
how the reliability is increased and what is the advantage of bigger range to work with?
sorry for my ignorance

jijita said:

what are the advantages of asynchronous ?
and innigel's tut about rs232 'The signal itself is slightly unusual for computers, as rather than the normal 0V to 5V range, it uses +12V to -12V - this is done to improve reliability, and greatly increases the available range it can work over '
how the reliability is increased and what is the advantage of bigger range to work with?

Click to expand...

Very basically the higher the voltage you use, the more you are likely to have left at the end of a long piece of wire 8)

The advantage of asyncronous is the reduced number of wires, syncronous requires a clock and a data wire, asyncronous only needs the data wire.

You also have to bear in mind how old all this sort of thing is, it was originally designed for mechanical devices like teletypes - computers basically 'borrowed' the various old standards.