Sampsa Laine wrote: On 8 Apr 2009, at 21:34, Paul Koning wrote: Sampsa> Anybody know how I would go about cabling such a beast, there Sampsa> are four fibre optic ports on these things? Wow, that takes me back a bunch of years... Well I do try, I'm going to wire up a CBM 128D running CP/M as the OPA0: on one of these eventually :) There are two basic FDDI cabling approches: dual ring, and tree of concentrators. The DEFPA can be hooked up either way because it has the two ports (type A and B ports). If you have other FDDI devices that also have A or B ports, just plug A to B in a circular fashion, and you have a dual ring. This is the topology that FDDI originally started with early in its development. So if I have two dual port PCI cards, one in machine 1, one in machine 2, I wire them: 1.A. -> 2.B 2.A -> 1.B No, 1. A -> B 2. B -> A to make a circle. Peace... Sridhar