On Wed, 5 Jan 2000, Chas Williams wrote:

> btw, i thought rs485 was a bus version of rs422.  it uses differential coding
> like rs422 but you can have multiple senders and receivers on the same
> set of wires.  i believe rs485 specifies some way of determining when it
> is clear to access the 'bus'

Both specs suport multiple receivers, but only 485 supports a real bus
concept. The mac serial drivers will support a bus topology (you can turn
the drivers on and off). Much more than that will be a matter of
programming. :-)

Take care,

Bill