Firewire fun?
 
 
 
 
 
 
 
I get quite a lot of stuff from a certain well known supplier of electronic spares. To save their blushes I won't name them. Generally they are OK and not as expensive as some even better known companies. However I did once have a problem with some IEEE 1394 (Firewire) cables which I had bought from them. The price was very good but when I enthusiastically plugged one in between my Firewire card (Fast DV Master) and my DV deck..... nothing. After some investigation I found that my new cables were wired pin for pin but my old cable which did work was wired with a crossover. At the time being very busy I tossed the new cables to one side till I had time to decide what to do. A few weeks later I was reading a new product brochure from the same company and came across what looked like the same (or very similar) cables. Ah! thought I, I wonder how these are wired? As you can see there is no real clue that there is any real difference between these cables except perhaps the price. Not wishing to buy even more cables which would not work, I picked up the phone to ask the company's expert what the difference between the cables (if any) was, explaining what I had found so far. OK now please humor me and read the product descriptions on the two clippings from their catalogue below:-
    
(Don't try to order the stuff from this site, It's just for illustration)
Now listen to this rather amusing audio clip. It's the message left on my phone in answer to my question.
You have a choice of either MP3 or RealAudioŽ. The content is the same.
Had the support engineer done much investigation before making the call? Well he may have done, but I can't help thinking that if his research had included his own company's catalogue description, he would not have used the term "Firewall Wiring"
I rather lost confidence in the tech support line after receiving the message, but a few people I was working with at the time had a good laugh listening to it. My new approach was to negotiate with the telesales lady. Firstly for a refund on the first lot of cables, and secondly for the second lot of cables on sale or return. This worked fine and the new cables are great! (This almost validates some of the info in the phone message, but I can't help thinking that luck played a part.) I'm left with one nagging doubt. Was the pinout on the first lot of cables a mistake? If it was then I could have got my cables cheaper, but so far I have not been able to find out if a cable wired pin for pin can be compliant with the IEEE 1394 (Firewire) specs or not. If you know the answer, please mail me at william@wmvp.co.uk.
http://www.skipstone.com/ has a lot of good stuff about IEEE 1394 (But even they don't seem to know)