Technical Difficulties from on Top of the Mountain
2004-10-16
  Lingering remnants of history
I resurrected my HP Kayak workstation this week. Having it working again, running X Windows on a HDTV class display, and in general just having gobs and gobs of desktop space is great, considering the machine has been offline for months. The inspiration came when I was replacing the power supply in fourth or fifth whitebox tower machine (Fry's blue light special), and I decided to pop the old one in the Kayak just for grins. Well, the power button didn't actually work, but the machine lit right up. It didn't get very far since I'd pull all the hard drives, and I was too lazy to even hook up power to the DVD drive, but it demonstrated that it would work.

Now I didn't want to put a crappy $10 newegg special in there, cause they're kind of noisy. Its fine for a server room, just not for my basement. Tim had been drooling over a super quiet power supply for his computer, because noise is an issue for him as well and pointed me at a few units he had picked out. Not wanting to spend $80 on model he found, I browsed up the newegg list just a bit to see what I could get for a few dollars more than the el-cheapo.

Turns out I could get a the same 120mm silent fan configuration for about $28. Only thing I'm loosing out on is efficiency. 65% is not great, but I didn't seen any higher efficiency models in my price range so that was it. Unfortunately that means I'm burning 170W just putting another 320W into the CPU & drives—a bit of a waste. But I plugged the new power supply in, which ran quiet as a mouse, and also added in a DVD+-RW(R9) drive which was ridiculously cheap, and for fun a $15 1000bT ethernet card.

Now, the funniest thing about the network card was not its ridiculously low price, but rather the plastic pack it came in. Not only did the plastic pack have space for the PCI card, but it also had this little spot for a historical relic that hasn't been used in over 15 years: a coax T connector.

Setting the wayback machine for the stone age of computers ...

See, back in the early days of ethernet, transport was over this huge triple shielded cable with the designation 10base5. (I don't know why it was called that, go look it up on Google if you really care.)


To connect to the network, each computer had a 15 pin port called the AUI which hooked through a parallel cable (drop cable) to the transceiver that then hooked to the 10base5 cable through what was lovingly called a "vampire tap". And these taps had to be precisely placed at 2.5m intervals so usually the main cable was manufactured with black markings at the appropriate interval. With the main cable costing upwards of $10/ft, the drop cables costing between $100 and $200 and the transceiver right around a thousand; networking was an expensive and complicated undertaking.

While transceivers eventually got smaller and somewhat cheaper, a lower cost solution was needed. Thus was born 10base2, based on a lower cost coax (RG58) cable. At first, an external transceiver was still used, but since there were no special length requirements, and electronics were getting more integrated, it became practical to put the transceiver on card itself, and just have a coax plug sticking out instead of the AUI. Usually however cards still had the AUI as well, just in case there was a 10base5 legacy network to talk to.

This format was a great improvement. Transcievers dropped to less than $100, cards to less than $200 (for PCs), and you could buy the cable cheaply in quantity and crimp the connectors on with a minimum of trouble. Local networks grew in leaps and bounds. Unfortunately as thinnet spread, there were problems.


Yes, I've seen a connection made this way. More than once.

Just because you could unscrew a BNC connector, didn't mean you knew what was going on. The BNC run represented a high frequency radio link between cards, and reflections or bad termination could royally degrade the signal. One area I was working in was computer graphics where we would move large (500k) files around by the dozen. (Ya, we were really pumping the network.) But graphics labs contain a large quantity of video equipment which is also hooked together using coax cable. Not the same type mind you, video used RG59 (75ohm) while networks required RG58 (50ohm); but unless you looked carefully at the printing on the jacket, you couldn't tell the difference. If someone needed an extra section of network cable and grabbed a piece of video cable ... well, lets say things were less than ideal.

The worst problem I ever saw was in one installation where they hadn't run the coax all the way down to the desktop in one office. They just ran it by in the celing, like in the old days of 10base5, then they put a transceiver on it, and ran a 15 pin cable from the transceiver down the wall to the back of the computer. Except they didn't use a big expensive sheilded drop cable like you should. No instead they used some penny-a-foot ribbon cable and two cheap press-on connectors. Still, they might have gotten away from it if the cable hadn't been running right behind a giant neon sign! Needless to say we were less than pleased with what all that noise was doing to the entire network.

So when 10baseT came out, with its immunity to noise, and easily crimped connectors (RG45s are basically 8 pin versions of a RG11 phone plug), and cable runs from each desktop to a central hub (or switch) where problems could easily be troubleshot; we were all over it and so was everyone else in the universe. 10base2 went the way of 10base5 and the dodo bird—extinct, except for the strangle little vestigial relic left in the plastic pack made for my modern network card.

 
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