[tulip] 21140 full duplex?

[Donald Becker]

On Tue, 17 Oct 2000, Dan Hollis wrote:

> On Tue, 17 Oct 2000, Donald Becker wrote:
> > On Tue, 17 Oct 2000, Dan Hollis wrote:
> > > Is it possible to do NWay in software or does this require hardware
> > > support at the chipset level?
> > The major feature of the initial 21142/21143 chip was the addition of NWay
> > with certain SYM transceivers.
> 
> So the 21140 is right out for NWay? Or can this be done from software and
> bit banging?

It's impossible for the 21140 with a SYM transceiver to do NWay.
The NWay negotiation signal is a special encoding of the 10baseT link beat
pulse.  There is no way for the software to modulate this.  See
  http://scyld.com/expert/NWay.html
for a technical description of how NWay works.

Donald Becker				becker@scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Second Generation Beowulf Clusters
Annapolis MD 21403			410-990-9993