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Admin
Last
Admin
And it took them months to fix this? RFI, I said to myself, straight away.
Admin
This implies the next TDWTF backup disaster is due this week.
(Pro Murphologist tip: Don't print this.)
Admin
IN GERMANY.
Admin
No cornify link?
Admin
Yes, we made this mistake in '82 so everyone else could learn from it. I think there was a patent issued and positioning cabinet sized computers in the middle of the room was a relevant part of it.
Admin
I'd have thought the rebar would act as a Faraday cage rather than an antenna, hmm.
Admin
You need a relatively tight mesh to form a Faraday cage. If you look at building structure of that time, the mesh wouldn't be tight enough.
Admin
Yes, it takes a while to diagnose/fix a bug that you literally cannot reproduce
Admin
Hmm. It was 1989. A computer hardware company was working on a wizzbang graphics card. The bench engineers loved listening to the local progressive rock station, broadcasting at something around 102MHz, in the lab.
But the unshielded prototype cards spewed radiation that stepped on the radio station's signal. So, they tweaked the clock on the card back, so it stepped on the local classical music station instead.
And they rocked out and finished development. Then, they ran benchmarks, and sure enough the card was about 5% short of the performance spec. Facepalm. Tweak the clock up. And the card stopped working reliably. Something about too much capacitance between some signal and +12V power. No time to respin the card before going to market.
That company isn't around any more.
Admin
Many, many years ago I worked for a company that used radios to communicate with technicians on their campus. We were changing workstation platforms from some Digital Pentium 133/166 boxes to Dell Pentium II computers. As workstations had to be worked on, we'd bring them down to our office and put them on the bench and we noticed something unintended. If the Digital computers had their case open and you keyed up your radio close to the workstation, it would do a hard power-off of the computer. It didn't happen with the case was closed, and it didn't happen to any of the Dells whether or not the case was open. Pranks ensued amongst the techs. (Oh, you were about done with that Ghost/defrag/virus scan...)
Admin
And this is a WTF? I thought the punchline of the story was going to be that there was only one outlet and somebody was unplugging the radio system power to plug in the computer and run the reports, would have been a much better ending...
Admin
The better ending is the one you see coming? Seriously!
Admin
Heh, yeah. This was actually a surprisingly good ending. The entire time I was rolling my eyes thinking, "It's going to be another tired cliche of idiot user unplugging the radio switch" and then finding that it was actually a rather unique edge case that truly needed someone to visit the site to figure out.
It's not a WTF in the sense that the customer was an idiot or the manufacturer was incompetent, but it's definitely a story that would invoke a "WTF" throughout the investigation from both parties until you reach the conclusion as to what the cause is.
Admin
I started work for the local school district in 2000. I was the only tech dealing with ~200 student-used PCs, so it obviously took me awhile to get around to problems. One computer lab, overseen by the business manager's wife, was having constant problems with 3 computers along one wall. I'd reformatted the hard drives, replaced the hardware with brand new machines, etc. They always started blue-screening within a couple of days. One thing I noticed is that the monitor in the center (15" crts) had an image that rocked back and forth constantly. The two monitors on either side rocked as well, but were less noticeable. Obviously there was EMI coming from somewhere. I looked on the other side of the wall for a breaker box, or water fountain, anything that might cause constant interference. I finally told the business manager that we needed to call in an electrician.
The electrician met me and the business manager in the manager's office. I explained what was happening and the electrician laughed at me and said it was impossible. The building was old with plaster walls. All the electrical runs were in conduit outside the walls with expanded metal mesh behind the plaster. Nothing in the wall or on the other side could radiate that much EMI. I insisted they follow me up to the computer lab. I pulled all the computers off the desk on that side of the room and plugged in one monitor from the center machine, and had it's alignment screen come up. I showed the electrician and the business manager that you pick up the monitor and move it around to essentially map the interference. The electrician said "Well, I'll be." and scratched his head. He told the business manager that he was probably going to have to rip out the conduit and outlets to fix the problem.
Later that day, the electrician calls my office and asks me to come up to the lab. He had the conduit laying on the desk and said "Look at this..." From where the wires exited the hole in the plaster wall and back into the segment of conduit that ran along that desk, the conduit measured an exact harmonic of the 60Hz AC power frequency. The outlet in the very center of that run had it's neutral wire jumpered to the ground screw. Being an old building, the wiring was 2-wires and there was no true "ground" apart from the neutral being bonded to the conduit. In that particular space with the conduit being that exact length, and the expanded metal mesh in the plaster wall acting like a reflection grid, the system turned into an antenna amplifying and broadcasting a powerful 60Hz signal from that center outlet what was jumpered to the conduit. Adding a real ground solved the problem. No more shaky monitors, no more blue screens (well, at least no more than was normal for Windows 95).
Admin
And it took them months to think about sending someone to the customer site? WTF???
Admin
It's called "Radiated Susceptibility"
Admin
A similar story from a bit more recently: An office was having horrendous networking problems, like frequent 90% packet loss. My computer services company's top hardware guy was eventually called in to their office to try and sort it out. And sort it out he did: They were using cordless phones throughout the office, and had strung up copper-based networking cables. The radio signal of the cordless phones was causing the networking cables to act as antennas and fuzz out the network packets.
That, however, wasn't an answer the owners of this company wanted to hear, so rather than, say, using corded phones or replacing their antiquated networking with fiber, they simply fired our company and continued to make their people just deal with the mess.
Admin
The real WTF is "cabinet-sized microcomputer". Microcomputers have that 'micro' in their names, because they are a lot smaller than those cabinet-sized computers this story is actually talking about.
Admin
That it was RFI was obvious. The source of the RFI, on the other hand, not so obvious as you seem to claim.
Admin
@Kaiserludi has not seen large tower cases, I guess, of the "you can fit 5 externally-accessible 5.25-inch devices in this case in addition to the floppy drive and seven internal 3.5 inch drives" type. And I direct your attention to the "drinks cabinet" in For a Few Dollars More for more on the relative sizes of cabinets and computers. Further point: microcomputers are so-called because they are based on microprocessors, not because they are mounted in small cases.
And on the subject of interference - around 2000-2001, I had a weird problem that people tended not to believe me about. My CRT monitor had a twitchy image. Eventually someone from IT support came up while it was happening, and went into the office kitchen and moved the microwave oven so it wasn't on the exact other side of the (thin) wall from my screen.
Admin
We had a similar situation, our twisted-pair AppleTalk network would stall out for five minutes at a time at random times. Everybody thought it was a software problem. Until one day I saw a nice old tektronix 555 scope out by the dumpsters. I lugged it into my office, tried it out, and it worked perfectly, if warmly, due to its 85 or so tubes. Gave the office a nice steampunk tech look. One afternoon when the network stalled I happened to glance over to the scope and it was showing a pattern of random noise, which it was picking up almost 2 volts of through an exposed test lead that was only three inches long! Yipes! EMI!
The next day I brought an old portable transistor radio and tuned it between stations. In about an d hour all of a sudden the radio sounded like a buzzsaw cutting through glass. I wandered around the building until the signal peaked, and it was right in front of a doc labelled "PLASMA PHYSICS LAB, NO ENTRY". I entered and the door was opened by a grad student, in a tinfoil suit and a gold-plated space-helmet. Behind him was a long glass tube with a purple arc running through it from end to end. I said "NEVER MIND"! There was no way we were going to get that fancy lab to shield themselves, we had to go shield our twisted-pair lines, as the twisting wasn't enough to cancel out all that arc energy being radiated.
Admin
Kaiserludi is probably confusing (the etymology of?) “microcomputer” with (that of?) “minicomputer”.
Admin
In 1982, true micro computers were like the Apple II -- they could not do very much. On the other hand, mini computers could do the things described in the WTF; they were usually housed in 19 inch racks. In Germany, they could have been using some form factor that is not common in the US, such as a Victor Nixdorf box.
Admin
I vote for this story to replace today's official story, which IMHO has absolutely zero WTF-iness.
Admin
I once had a twisted pair network I administered in an architect's office 1990. It was from a company called 10 Net networking. I had networked about a dozen PC's together and the bosses thought it was the coolest thing. The talked up how advanced and cutting edge their office was and how it helped productivity. That was all sales bunk to convince customers to use the architect's service.
The thing worked fine in the morning. By 11:00 AM PC's started dropping off the network. They would drop off in order starting from the same end of the network each day. By 1:00 PM no PC could see any other PC. At 4:00 PM the PC's would appear on the network in the reverse order of their disappearance and by 5:30 PM everything worked normally.
The problem did not occur at all on the weekends.
I used to run a carrier current AM radio station. I learned a lot about how electrical loads change the overall impedance of wiring in a building. This reminded me of that situation except this was not carrier current. Some how the impedance between the computers changing. This was interesting because they were all about 5' apart from each other.
I curious and pulled an electrical outlet out of the wall. I see hot, common and ground. Odd the ground looks a bit slack, tug on it and it is a 6 in pig tail stuffed in the conduit. No ground, that would sure screw up the impedance. It turns out nothing in the building was grounded. The electrician cheated on the installation.
After everything thing was grounded the network was stable for years until it was replaced.
Admin
In the 70's the company I worked for sold newspaper production systems. At one site, the computer crashed at (let's say) 5 PM. When you have a bunch of motors spinning up thousands of pounds of lead printing plates there's a bit of a voltage surge.
Another site would have all the terminals crash at random times. The computer room was a floor above where the terminals were located, and the cables had been routed through the freight elevator shaft. But those are coax, and coax is shielded, you say? Yes, but the terminal manufacturer wa using that coax because it was a cheap way to get the correct impedance, and the "shield" wasn't grounded. It was basically being used as an unshielded pair.
Admin
!982 in Germany? Which Germany?
Admin
...Here's the link: https://books.google.com/books?id=5gEAAAAAMBAJ&pg=PT38&lpg=PT38&dq=large+tower+case+40+pounds&source=bl&ots=ToqNBl1sY9&sig=dFzZPQlat3i_1VmduG36RTtp4JM&hl=en&sa=X&ved=0ahUKEwiFwbjIturOAhVR9WMKHSCYCEoQ6AEIUTAA#v=onepage&q=large%20tower%20case%2040%20pounds&f=false
Yes, a case can weigh 40 pounds (~18KG) completely empty.
Admin
Wow, did that link get mangled...just google "large tower case 40 pounds" and pick the first result....
Admin
Anonymized, d'oh. Why'd you change the wording of Buggesellschaft?
Admin
All you people talking about twisted pairs don't know what twisted pairs are. Here's a twisted pair:
http://tonyfisherpuzzles.net/images/SiameseCubes.jpg
Admin
Always keep the switch set to "more magic"!
Admin
Rebar... antennas in disguise!
Admin
When a certain bank in the UK used to use SDX telephone systems we would often get a call regarding a faint buzzing on on of the handsets.
Convincing the user that this was interference from a BLOWN halogen bulb in one of their up lighters was often quite dificult (altill you get them the switch of the lights & the noise stops).
We also had a nother case of random ticking on the line that was eventually traced to an electric fence on a nearby dairy farm
Admin
At the bottom of the linked page, there is a listing of the components for the 'Dream Machine 2000'... Total cost $11,987!!!!!
Overkill, just like the case
Admin
The place where I work had (until recently) an 800MHz trunking radio system. We could never get anything to work reliably on 802.11b/g. Took a little bit to join the dots that it was the third harmonic being emitted from the handheld transceivers that was killing it. We've since gone to a TETRA system.
Admin
982 it would have been the Holy Roman Empire, but computers would be an unusual sight
Admin
Tell me, tell me, where is "Frequenzhof" located? I get "Busgesellschaft", aber was zum Fick bedeutet "Frequenzhof"?