appel's desktop bus works lik this there is an appnote on microchip's
website  an519 i improved the code for differend application apple
allowed 16 device's to be connected to the Adb bus works with polling
by the host

greetings an happy christmas to all
Marcel
M.v.d.Bilt@fibre.A2000.nl

Donald L Burdette schreef:

> There's a simple way to "or" the slave TX lines with just one resistor.
> Just tie several open collector outputs together and use a single pullup
> resistor.
>
> Almost all Microchip I/O pins can be configured as open collector.  Set
> the data register to 0, and write the data to the direction register.
> When the data is "1" the pin is tri-state, when the data is "0" the
> output pulls low.  I've used this method to tie several Dallas 1-wire(tm)
> parts to a single I/O pin.  That's why they call it 1-Wire!
>
> Such a configuration is not high speed compared to RS-485, but it could
> go at 19.2 kBaud over 20 meters without even really trying hard. I've
> worked it at equiv to 9.8 kBaud at 300 meters.   With 2 or 3 line
> protocols you could go significantly faster.  Is 19.2 kBaud fast enough?