The adapters are a good solution for habitual scroungers, since they come cheap, but dual speed hubs solve the problem handsomely. They use the signaling voltage to distinguish between the standard and fast ethernet connections and happily route to both connection types. Unfortunately that may have some drawbacks, e.g. now your unified segment ( the dual speed hub does that ) operates at either speed, but at an aggregate rate equivalent to the slower. I use separate segments for the fast and standard ethernets, though I have a single segment consisting of standard ethernet on RG58 and twisted pair via a hub which is attached through one of those little AUI<=>coax adapters. Dick -----Original Message----- From: Daniel T. Burrows &lt;danburrows(a)mindspring.com&gt; To: Discussion re-collecting of classic computers &lt;classiccmp(a)u.washington.edu&gt; Date: Wednesday, October 27, 1999 4:52 PM Subject: Re: Semi-OT: Running CAT5 Cables connection transceivers.