From: Stefan R. <st...@s5...> - 2011-01-14 14:34:39
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On Jan 14 Jonathan Woithe wrote: > Damien Zammit wrote: > > This is a bit of a long shot... Has anyone got a newertech cardbus > > firewire2go card or used one? I sourced one but the owner says it > > doesn't come with a dongle. Is the dongle necessary for operation? > > I am not familiar with this card and I don't know what the "dongle" is. Almost all FireWire CardBus card have a bulky exterior plastic part which contains the FireWire ports. Newer Technology FireWire 2 Go had a short cable instead which was plugged with a flat connector into the CardBus card and had a female FireWire 6-pin plug on the other side. At least this is shown on pictures of this prodcut on the web. But who know, maybe there were later product revisions with a different form factor. Or the seller does not associate the term "dongle" with this breakout cable. > Euan de Kock wrote: > > I bought a "Solectron 1394 PCILynx PCI 3-port FireWire Card" off ebay, > > and this works with the nosy driver. [...] > > For some reason I could not sniff the Isochronous traffic unless the > > nosy card was in the centre. > > I think that's because a firewire node is only required to forward an async > packet onto its other ports if that packet was not addressed to it. > Therefore an audio interface may not echo a packet onto its second port if > that packet was destined for itself. No, it was either because some components were faulty or because the connection speed between the other nodes was higher than the PHY speed of the PCILynx card. AFAIR there were very early PCILynx cards which were only S200 capable. Have a look at IEEE 1394-1995 clause 4.4.1.2 or at IEEE 1394-2008 clause 9.2.9.2. Everything which is received on one port is repeated on all other ports. (As a special case, if a connection on a repeating port is slower than the rate of data reception, that port merely transmits data-prefix instead of data.) This is not very obvious from the spec, in the current edition even less so than in the 1995 edition. But e.g. Don Anderson, FireWire System Architecture, 2nd Edition 2003, spells it out on page 59. (The last sentence on that page is wrong though; the function which is described there resides in the link layer --- from a layer architecture point of view, not necessarily from an implementation POV. But this is immaterial to the PHY's repeater function.) -- Stefan Richter -=====-==-== ---= -===- http://arcgraph.de/sr/ |