Computer Voodoo? 686
jbeaupre asks: "A corollary to 'Any sufficiently advanced technology is indistinguishable from magic' is that sometimes users have to resort to what I call 'computer voodoo.' You don't know why it works, you barely care how it works, but you find yourself doing the strangest things because it just seems to work. I'm talking about things like: smacking a PC every 5 seconds for an hour to keep it from stalling on a hard drive reformat (with nary a problem after the reformat); or figuring out the only way to get a PC partially fried by lightning to recognize an ethernet card, after booting into Windows, is to start the computer by yanking the card out and shoving it back in (thereby starting the boot processes). What wacky stuff have you done that makes no obvious sense, but just works?"
For most problems... (Score:5, Funny)
Re:For most problems... (Score:5, Funny)
Re:For most problems... (Score:5, Insightful)
Actually, to be honest, I find that creating an incentive for the user to understand the technology is a much better long run solution. The average person nowadays can accomplish an awful lot with a very basic, approximate functional understanding of the system. Unless there is some reason that they need to learn the details, they will likely never do so.
The truth is that this does not merely apply to "lusers," but to many of the most brilliant programmers you'll find. How many programmers know the deep details about the electronics that make up the processor? Or about the connection between doping, band-gap effects, and statistical mechanics that regulate the real-world execution of logical operations? I have dual degrees in Physics and CS, yet I would not include myself in that category.
I think what we need is users that aren't necessarily "theoretically" educated (this can, in practice, be quite useless), but rather have the appropriate metaphors (pipes, not tubes) to understand the majority of what to do in a given situation. Know what different symbols and actions connote, and where to find help (besides just asking the "computer guy").
Re:For most problems... (Score:5, Insightful)
Even understanding the architecture of your processor is only of value to some programmers. For most, it's better to understand the programming model for the particular language being used and tailor your program to that abstraction. Trying to apply knowledge of the low-level architecture in high-level programming is a recipe for over-optimization, especially if that code ever gets ported to another architecture.
Now, in the latter case, I will grant that it's indispensible to have learned the details at least one computation architecture through and through at some point. It almost doesn't matter what it is, since it's the process of stepping back and thinking about how to construct machines that compute that is the enlightening bit. It's really astonishing how "dumb" the logic behind a really "smart" processor can be. However, day-to-day, it's very rare to actually need to apply details for the specific machine you're using.
If you're writing DSP code or other real-time embedded stuff, this is obviously different, but that's a very small subset of all programmers.
Re: (Score:3, Insightful)
It's not useful for programming, but that's not what this article (or my post) is about - it's about using and fixing computers. All the software knowledge in the world doesn't help you when it's
Re: (Score:3, Insightful)
That's where spending time fixing all kinds of eletronics (stereos, TVs, VCRs, cassette tape recorders, 8 track players, reel-to-reel tape recorders, fish locators, film projectors, overhead projectors, computers, packet assembler/disassemblers, etc) grants a kind of insight that theoretical background might not give you.
Oddly, sometimes it seems that its not saying the exact
Re:For most problems... (Score:5, Funny)
All misspellings and grammatical errors in the above post are intentional and part of my artistic expression.
Not reading manuals is a pebkac error. To fix this problem I recommend replacing the user.
Re: (Score:3, Insightful)
Re:It is modded as funny beacuse is nonsense. (Score:4, Insightful)
The average user doesn't give a damn how it works, doesn't care if their own actions are contributing to the failure(s) experienced, and will resist being educated. The technician who is called in after-the-fact is only half of the equation.
The way most users handle computing could be compared to approaching your doctor, complaining that there is something wrong with you, and then putting your fingers in your ears and saying "BLAH BLAH I CANT HEAR YOU!!!" when he gives advice or asks if you are willing to undergo some tests. Oh, and then getting pissed off at the doctor when you have the same complaint again. Now, would you say this is the doctor's fault? Similarly, the best technician in the world needs someone willing to work with them in order to truly solve problems instead of merely applying band-aids.
Re:For most problems... (Score:5, Funny)
Re:For most problems... (Score:5, Funny)
I quite agree.
See you Monday. Bright and early!
Re:For most problems... (Score:5, Funny)
Re:For most problems... (Score:4, Funny)
Mr. Duvalid, this is YOUR boss. I see that you posted on Slashdot one minute before you clocked out. Come see me Monday morning, bright and early.
Re:For most problems... (Score:5, Funny)
You forget that I wrote the timeclocking system.
You better see *your* boss bright and early
Monday morning. Remember, I read BOFH nearly
religiously. Dont make this too hard on yourself.
Duhavid
PS: What is this "clocking out" thing you talk of?
Re: (Score:3, Funny)
I wish my boss was a deer... Just a little peanut butter, and he'd always be happy.
Re: (Score:3, Funny)
Ditto. If only I were a masochist that would work out just fine.
KFG
Re:For most problems... (Score:5, Interesting)
Of course, as far as real Computer/Equipment Voodoo is concerned, there is always the Heisenbug [wikipedia.org]. Just had a mechanical version of this today, the Bayer tech has spent 3 days on a machine to isolate a pump problem. To see the pumps, you have to open a panel either on the side or the front of the instrument. The past 2 days, he was working on it through the front, and the problem didn't occur. Today, after being called back because it happened again, he opened the side panel to watch it, and accidentally bumped the front panel while he was looking at it. As soon as the front panel closed, the problem occurred. It turns out that a zip-tie that holds some tubing from the pumps together was caught on the front panel, and when the panel door closed, it pulled on the zip-tie, which pulled on and pinched the tubing, causing a pressure sensor to throw a fault.
Gonna Date Myself Here (Score:3, Funny)
Once upon a time, CD burners were a very new thing. We had just gotten one in at work. We didn't burn much because the disks were expensive. This new guy started in our shipping department and he asked if we would copy a game for him if he bought the disk. We told him that would be fine. He brings in his software and his blank disk. We carefully put everything in the machine and set the disk to burn.
When it's done, I very calmly pull some oven mitts out
one time at computer camp... (Score:3, Funny)
now thats voodoo
Re:one time at computer camp... (Score:5, Funny)
Re:one time at computer camp... (Score:5, Funny)
I've got the touch (Score:5, Funny)
Re: (Score:3, Funny)
My boss has exactly the opposite talent. If something is working perfectly and has been running properly for days, weeks, or even months, it will go haywire thirty seconds after he walks up to look over your shoulder.
hitting it (Score:5, Informative)
Re:hitting it (Score:5, Informative)
Re:hitting it (Score:5, Interesting)
Re:hitting it (Score:4, Funny)
Nobody wanted to tell him that moving the mouse by hand would have the same effect...
Not sure how it works... (Score:5, Interesting)
Re: (Score:2)
Re:Not sure how it works... (Score:5, Informative)
IDE drives keep a list of spare sectors to be used if one of the "primary" ones gets damaged. However, if a sector gets damaged and it already contained data, the drive won't reallocate it, because it would have no way of recovering the information. So it keeps "hoping" that some day the data will be readable again, and when that happens, it'll reallocate the sector. However, it never happens.
When you overwrite a defective sector, the drive says "aha! since the user overwrote the information, it means it's not important anymore; so I'll go ahead, mark the sector as bad and replace it with a spare". That's why overwriting gives the drive a chance to remap all bad sectors to clean ones.
This is a trick I learned by reading the documentation on smartd; if SMART reports defective or unreadable sectors, there's a way to figure out which files reside in those sectors and overwrite them with zeroes; the file will of course be lost, but by overwriting you let the drive reassign the sector and everything is peachy again.
By the way, if you reformat the drive with the destructive verification option (-c -c) it's likely that when the test overwrites to verify readability, the same reassigning process will take place; the standard "-c" test is a read-only test that's why you're unable to format a drive without the overwriting procedure.
So you see, not voodoo.
Also (Score:3, Informative)
Re: (Score:3, Informative)
Both. :-)
As far as I'm aware, all (E)IDE, SCSI and (S)ATA drives have spare blocks that are used for remapping blocks that fail whilst the drive is in service (incidentally, I suspect that SCSI drives have significantly more, which would go some way to explaining their lower capacity/platter ratio and higher MTBF ratings, beyond the pure mechanical stuff and individual rather than batch testing).
In addition to tha
Re:Not sure how it works... (Score:5, Informative)
Mod parent up!!! (Score:5, Informative)
Again, great little one liner command to remember in the tool bag...
Re:Mod parent up!!! (Score:5, Informative)
This is one of the 'gotchas' with multimedia content. A hard drive may have fast access times and a fast bus, but if there are persistent CRC errors (and there is quite often CRC errors on a non-failing drive!), then the drive may have to take 15 or so separate reads of the track to reconstruct - It may also temporarily move the surrounding tracks to the secret area, then zero out the surrounding tracks in order to reduce track-to-track crosstalk.
All of this takes time, and quite often any real time media bandwidth budgets get blown when this happens.
The neat thing is, when this does happen, it is never an error. The program does finally get the data, but it just takes longer than expected. Typically one way to find out if the drive has remapped tracks on you is to have a program which measures track to track access time sequentially, and find the track boundaries that take a lot longer than a move from adjacent tracks should.
Jeff
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Speaking of hard drives (Score:5, Interesting)
Anyway, I used to have three or four MFM hard drives in various states of disrepair. (I think they were 40 *meg* hard drives, but I only had a controller to control up to 20 meg, to give an idea how old this hardware was.) One by one they died, until finally only one was left. When it gave up the ghost, it would spin up, then immediately spin back down. I dug into it and found some connections I could short across while it was spinning up and then break the connection, and it would keep running. I was too poor to want to go spend $1 on a pushbutton, so I just had two wires hanging out of the front of the computer that I held together while booting the PC. I ran it that way for over a year...
A non-computer story, but more interesting one, is of an old Ford Escort I used to have. The starter went out on it, and, again, I was poor, so I dug into it. I finally figured out that the relay was kicking out too far and shorting out against the housing, so I duct taped a kitchen sponge to the inside of the relay housing and put it back together. I never had a problem with the starter again for the 2 years I had the car.
That same car later had the fuel pump go out. When it went out, I asked my stepdad if I should check to make sure the pump was out instead of a wiring or power problem, and he said nah, it's the pump. So I bought a replacement - it didn't help. So, I hunted around under the hood until I found some leads that were hot when the key was on, but not when it was off, and I used ties to secure an extension cord from the leads to the fuel pump. The car ran fine.
That was in the summer. When winter came along, one day I needed to defrost the front window as I was driving down the road. I flipped the vent from dash to defrost, and the engine stopped running. (I was doing 50 mph down the road at the time.) I flipped it back to vent, and the engine started right back up again.
Somehow I had found a wire that only gave power when the vent was not on defrost. I never fixed it, just kept the inside warm enough that it didn't frost over.
Now I'm a software developer and not poor. I virtually never fix (or jerry rig) anything myself, other than software and the occasional computer hardware issue.
Re:Not sure how it works... (Score:5, Insightful)
The only thing left to add is that doing
should be significantly quicker.Oh, and the other thing is that, these days, I tend to run badblocks' write-test on new drives, in an attempt to get the drive to remap any failed or marginal blocks before putting Important Information on them.
hard drive (Score:5, Interesting)
Re: (Score:3, Interesting)
Walk into the room (Score:4, Funny)
(until I leave...)
Re:Walk into the room (Score:5, Funny)
-- Shade
Machine Empathy (Score:3, Funny)
Machine Empathy is a mutant power that makes all things electronic (be they computers, appliances, or killbots) into your best friends.
I submit that people who program computers, and like computers, naturally develop this mutant power.
(Incidentally, the best part of the game was that computer programmers were called "high programmers" and were worshipped (and feared) by the rest of society. That is how it should be.)
Re:Walk into the room (Score:5, Interesting)
I've seen other situations like this. Many times, it's because the user is doing something they know is stupid/they shouldn't be doing, and with a techie looking over their shoulder they don't do it.
Re:Walk into the room (Score:5, Insightful)
Except that the step WAS crucial, and now it works. They had some other problem, and they'd fixed it, but now by skipping that step they still get the problem.
I wish I could attribute that just to dumb users, but I've made that mistake myself. "Yes, I TRIED rebooting the router... oh, it worked this time. Never mind."
Re: (Score:3, Interesting)
Re:Walk into the room (Score:5, Funny)
Turns out he touch typed while sitting, but had to look at the keyboard while standing - and since he "cleaned" his keyboard and put a few key tops back in the wrong places, he was mis-typing has password if he was standing up.
Re:Walk into the room (Score:4, Informative)
Computers mysteriously start working again when you enter the room? Feh. This hardly qualifies as Voodoo. I mean, it's got a perfectly rational explanation [catb.org]:
Re: (Score:3, Interesting)
As it is now, my fiance (I know- invoking mythical creatures on
I guess my best bet is to c
Hard Drive Massage (Score:5, Interesting)
In my repair monkey days, my shop used to handle data recovery jobs of all kinds. The problems ranged from minor filesystem corruption or unbootable drives to physical damage - heads, and even a bullet through a hard drive (No, I wasn't able to get anything off that one).
We had a variety of methods for dealing with the physically damaged drives that had suffered a head crash, but my boss had a technique he called the 'massage'. A clicking or noisy drive would be rotated around its various axes until the BIOS would recognize it on boot. Sometimes the clicking would stop and he would sit there holding the drive in that position or prop it up to keep it there.
Another method we used was to freeze the drives for a period of 15 minutes to 6 or 8 hours. Sometimes this allowed enough contraction to let the tracks line up again, and we'd get as much data as we could with the drive cold. Once, we even froze a drive between two ziploc bags of water with IDE and power cables hanging out the edge to keep the drive colder longer. It worked!
-- Shade
Re:Hard Drive Massage (Score:5, Informative)
Re: (Score:3, Funny)
Re: (Score:3, Funny)
7-second rule (Score:3, Interesting)
Re: (Score:3, Interesting)
Or maybe just voodoo...
Performa 5200 and the mouse vs. network ritual. (Score:5, Interesting)
Read that second link for all the gory details of why the follow scenario works, and you'll shudder.
I used to note in college that when doing particularly fast FTP transfers that saturated by 10-Base-T card that the machine would often lock up within a minute of starting the transfer. For months, I fiddled around and noticed that if I was actively working that this didn't happen. Eventually, I found the article I mentioned and realized that if I kept moving the mouse constantly, the machine wouldn't get in whatever weird state locked up the machine and I could finish my transfers. That's right -- to run FTP (or any other sustained, saturated transfer), I had to sit there moving the mouse in circles through the entire transfer.
Essentially, the "Left 32" bus described in the article was shared by the 16-bit Apple Desktop Bus (for mouse and keyboard) and the 16-bit networking card (as well as audio and the 8-bit SCSI controller). So long as I kept interrupting the bus with input from ADB, the networking card was unable to flood the controller that had to make sense of all the different bit-widths and clock speeds between the various busses hanging off of it, and the machine wouldn't lock up.
Now how's that for some serious computer voodoo?
Re: (Score:3, Interesting)
I also remember my old Tandy COCO Days with my external 300 Baud modem... I could dial into Delphi but I couldn't start pressing keys or the Term Program I wrote would fre
feeling better, thank you (Score:5, Funny)
I gotta stop using gentoo.
Random Cursing and Hitting (Score:5, Funny)
TV Card (Score:3, Interesting)
My analysis? (Score:4, Insightful)
The same is most likely true with the ethernet card.
The motherboard itself may have something loose, and the way to deal with all of it is to move components into other PC's and see how things go.
I've seen and met all hardware problems and beat 'em all (even if by buying a new component). The REAL voodoo lies in the software. Why in God's holy name does Windows fail to boot one time, and then boot successfully the second time?
Re:My analysis? (Score:5, Funny)
Hardware problems.
Re:My analysis? (Score:5, Funny)
Do you mean the first time or the second time?
Re: (Score:3, Interesting)
Long story short... there is one screw in the motherboard that if I tighten it down... the motherboard doesn't work. You can't believe how long it took to find
Re:My analysis? (Score:5, Interesting)
Hah. I had something close to that one. A friend's Windows XP Home system. Boot it up, runs fine for about 30 seconds, then locks up hard. Reboot it, works fine for as long as you like. Next time you boot it up, locks up after about 30 seconds. Reboot, works fine. Lather, rinse, repeat.
I booted it up off a Knoppix disc and ran a bunch of hardware tests -- nothing. And no problems with locking up either.
Back to Windows -- same thing.
I eventually realized the pattern: after a clean Windows shutdown, it would lock up 30 seconds after the next boot. After a dirty shutdown (e.g. power cycle or reset button), it would boot up fine. Obviously the Windows shutdown was leaving something in a funky state for next time. Beats me what.
I told my friend she had the choice of doing a re-install and keeping fingers crossed, or always shutting it down with the power switch, or moving to Linux. I don't recall what she did beyond passing the box on to her kids because she'd already got a new one for herself.
Wireless (Score:5, Interesting)
However, after I installed the card, Windows 2000 would crash with the following BSOD:
Annoying as heck-- somewhat expected from a cheap network card.
So one day I was wat home downloading Fedora with bittorrent--- my DSL connection was maxxed out. There was too much interference on the line, so I hit the little 'channel' button to switch to a different channel.
As soon as I hit the button on the phone -- *boom*, the computer threw up the Blue Screen of Death. ANd sure enough, I reboot, hit the button on the phone-- and *boom* -- Computer crashes again.
I have since replaced all of the D-Link cards with cards from other manufacturers.
Funky Hardware Stories (Score:4, Interesting)
I used to have an old pentium (133 I think) that ran well, except that the CD drive would only actually recognize a disk if you tilted the computer at about a 20 to 30 degree angle when the disk was inserted. I never did figure out why this fixed it, luckily I didn't need to use the cd drive very often.
I also used to have a cable modem that would drop the connection if you so much as blew on the power cord. I always just figgured that was just some flaky hardware, and eventually got the cable company to replace it. Another really aggrevating hardware problem that I never figgured out was an old Sony DVD drive that I had. When you opened the tray, it would about 1 to 2 seconds later automatically close the tray, but when you opened it again it would stay open for about 10 seconds, just long enough to remove or insert a disk.
I think everyone runs into a situation where there is some voodoo involved in solving a problem, it becomes problematic when people stop carying about having any answers, and just care about getting something working.
Cold boots only (Score:2)
Not a computer one, but... my high school's music teacher had an ancient stereo amplifier that would make the sound muddy every few minutes. The solution was to knock on the case at a certain spot until the sound cleared up.
chkdsk. (Score:2)
It runs perfectly stable.
But when I reboot, windows pukes, hard. It will refuse to boot completely even in safe mode until I run chkdsk. Chkdsk doesn't seem to find or fix anything, but once it finishes everything works fine.
More Magic? (Score:5, Interesting)
Got to love old school hacking
Always remember... (Score:4, Interesting)
Re:Always remember... (Score:4, Informative)
The POSIX semantic is: sync() doesn't have to actually write everything, it can just schedule the commit. However, a second sync() won't return until the writes from the previous sync() finish.
On Linux, a single sync is enough, though.
Complexity (Score:4, Insightful)
'Magic' is when a device does something well, which one did not expect technology to be able to do, and in a way that does not make it obvious how the technology is implemented.
The story is about when devices do not do what they are expected to do.
I had a motherboard... (Score:3, Interesting)
That wouldn't boot up unless freon spray was applied to the area just under the processor. (Okay, it wasn't real freon, but the CFC-free stuff...)
It seems that it had a few "cold soldered" joints on an IC or two, and freezing it brought them back into contact with each other.
This works every time (Score:5, Funny)
Tell the enduser their network cable "got reversed" and somebody will have to go over there and turn it around for them.
First, if you ask someone to put the phone down to check for link light, they'll answer back in 3 seconds without checking.
Second, even if they actually wouldn't lie about it, they'd never get under a desk to fix it in the first place.
Even guys in suits do it every time, if you say someone will be over "later" to reverse their (known loose) network cable.
End result -- works every time if you do it right, and no credibility lost since everybody understands what happened.
"You are a pirate!" - Microsoft (Score:5, Interesting)
Re: (Score:3, Interesting)
A few years ago, my pc started randomly turning itself off while I was using it.
During the course of swapping parts in an out of the motherboard and trying to boot the computer to see if a specific component was causing the problem (it was the power-supply, duh!), Windows eventually got to a place where it needed to be reactivated.
The network card didn't function anymore because its driver had been uninstalled (???) during the tests.
I didn't feel like spending any time on the p
Not exactly on topic but close (Score:3, Interesting)
As for being on topic...I can guarantee that shit will break everytime I try to take a long weekend or vaction. The corollary is that everytime I'm on site for a "just in case", I end up not being needed.
RE: Entrails (Score:4, Funny)
Dowsing for bad RAM chips. (Score:5, Funny)
I remember when I was a little kid, I used to watch the old Tom Snyder Tomorrow show on late night TV, and some weird guy demonstrated how to dowse using a couple of bent wires made from coat hangers. I was skeptical, but eventually I became known for some rather startling dowsing stunts, I used to challenge people to hide my keys in a location I was unfamiliar with, in houses or buildings I'd never been to, and could find them 4 times out of 5. So when I became a computer tech, I figured, what the hell, it couldn't hurt, it couldn't possibly take MORE time to try dowsing than to do the elaborate binary search method. And to my astonishment, it was a LOT faster. Sometimes it took me a couple of tries, but pulling just a couple of individual chips was a lot faster than pulling 12 chips at a time, and my results were way above the expected average of just pulling a chip at random. BUT.. I made absolutely sure that nobody ever saw me dowsing on their machines. This is Computer SCIENCE, after all, it isn't computer VOODOO. Ha!
Re:Dowsing for bad RAM chips. (Score:4, Interesting)
Well, the short answer is, because that was Apple's official service procedure.
The binary search method is theoretically the fastest way to identify the bad chip. This is a basic comp sci search algorithm, if I remember the it right, with 24 chips, you can identify the bad chip in 4 swaps. Replacing chips one at a time is, on average, the worst way to find one bad chip. Of course you could get lucky and it was the first chip you replace, row 1 socket 1. How often is that ever going to happen?
Also consider that the RAM diagnostic program could run for hours to run before a chip faulted, so swapping chips was not always the most time-consuming part of the test procedure. I sometimes used to speed up the process by gently heating up the motherboard with a hair dryer, on the theory that intermittent chips were more prone to failure when they were hot, but this was not usually effective.
Also consider how expensive RAM chips were back around 1980. We were NOT going to just replace every chip until we got the bad one, we only replaced known bad chips, if we pulled out chips, once they were ruled out as not the cause of the problem, they went back into the customer's machine. Otherwise we would have ended up with drawers full of suspect chips, and customers would have had to pay for every single chip we replaced. Labor was much cheaper than parts, back in those days.
Now I'll tell you what REALLY hurt.. when I had to service a machine that had TWO bad chips.. but fortunately, that rarely happened. They almost always went bad one at a time.
Dr Who (Tom Baker) was here first (Score:3, Interesting)
He stumbled across an old spacecraft on a very distant planet. As he sat down at the control console he remarked, "this looks like Earth technology". As he began to power it up it slowly came to life then started to fade back out. He kicked the bottom of the console and the rocket resumed slowly coming back to life. The Doctor remarked "Definitely Earth technology".
I just LOVE the implication that this sort of "kick it to keep it working" is a characteristic aspect of our technology that (in the world of this SF TV show at least) sets us apart from other species.
Most of it is Microsoft... (Score:3, Informative)
Back in the DOS days, people were convinced things worked better if they left the power off for long periods of time, before restarting.
Windows got more complex, and had too many of those things to name. Hitting the tower is a popular one. Moving the mouse around while waiting to prevent lock-ups is another very popular one. There are certainly millions of them. Linux, too, has developed a few, because some drivers are iffy, but they make up the tiniest fraction of what you see with Windows zombies (aka. users).
When I'm helping someone with a Windows system (I keep that as rare an event as possible), I still see similar nonsense. Windows XP's setup will allow me to partition hard drives #1 and #2, but WON'T let me format them there, and I have to put them in another system to do that part. Not to mention all the drivers that will just corrupt themselves after working fine for 3 months, if you just LOOK at the system funny. It's no wonder voodoo is so popular with Windows systems (and pre-OSX Macs, to be fair).
.
With that said, I have seen some frustrating hardware problems. After 6 months of working without any problem, my always-on Linux system starts crashing every day for 3 days, and then won't start up... Typical crappy power supply (bloated capacitor).
I had a Charter cable modem which would work whenever the tech guys were here (I called them out a dozen times over 2 months), but would fail miserably just moments after they'd step out the door. It took me a while before I realized that the thing would work for amout 5 minutes after it was power-cycled, and only then would it crash. They would never take my word for it, and I had to cancel my service to get rid of that piece of shit.
I've seen a few network cables, which test-out just fine, and work most of the time, but after the machine has been online for a while, it will fail, and need to be rebooted... This is partially Windows voodoo, because the stack is unstable, and can't handle many errors. But mainly, it's because of cables with marginal connections, which work about 95% of the time, enough to pass tests, but cause all sorts of problems in real-world use.
Then there are the occasional network cables with crosstalk, which can be hard to diagnose if you don't have an advanced/expensive meter, and give many of the same symptoms as above.
There was one case where a guy would play music CDs for an hour, before they started skipping. He changed CD-ROM after CD-ROM, before asking for my help. It was pretty obvious when I saw the sheer ammount of lint in his system fans. It would run fine while the system was cool, but the fans not spinning would drive the tempurature up to insane levels shortly, and the CD-ROM was just the first part to show symptoms.
Another Windows one is IE's download dialog... It takes so long before it appears, that when it starts there is already a few KBs downloaded, so it claims a 500KB/sec download rate on a dial-up modem, and only gradually goes down to about 4K, as it's really doing. People think that's accurate, and actually come up with the great idea of stopping and restarting downloads several times every minute, presumably because the server or their ISP will only allow them to download "fast" when the download first starts.
God I hate Microsoft...
....Obvious Answer (Score:5, Funny)
What wacky stuff have you done that makes no obvious sense, but just works?
Ask Slashdot.
(...though I'm not quite sure it works...)
Homemade "Apple" Intel (Score:5, Funny)
One day I'm playing Serious Sam over the LAN with some friends. There's a brief lull in the action and so I reach over for the 1 gallon bottle of apple juice I was drinking from. Well, instead of picking up the apple juice, I tip it over and the entire contents spill out ON TOP OF the Compaq. I of course, immediately jump in to disaster recovery mode and race to the kitchen to grab the paper towels. I start cleaning up the mess, expecting the wrost for the Compaq in the process. I could see where there was apple juice in all of the little crevices and I'm darn sure some of it actually got into the computer. Some had spilled on to some school papers lying next to the machine and I wanted to make sure I didn't lose any notes so I took plenty of time to salvage those papers.
After I finished cleaning up the mess, I check the computer. Mouse and keyboard input seem OK. I start up Winamp and it seems to work OK. I run scandisk on all of the drives and they all report being OK. I can't find a single thing wrong with this computer. And I'll be damned if that computer didn't have a single random reboot after I spilled apple juice on it. It became the object of admiration and jokes amongst my friends, and one friend even managed to find one of those fruity, rainbow colored Apple Computer stickers that he wanted me to put on the case. I never even bothered to open up the computer to asses the damages (partly becuase I was lazy and didn't have a torx screw driver at school). Truth be told, I was afraid to even move the comptuer or otherwise disturb it since it seemed to be working OK.
A quick addendum to this story... right before graduation I purchased another hard drive for my primary desktop machine that was about 4 times the total capacity of the drives in the apple computer. I copied all of my data off the apple computer on to this drive and pretty much relegated the apple solely to web surfing detail. About a year and a half later, I need another hard drive for a client machine and so I decide to finally open the apple computer to raid one of the hard drives in it. I was even more amazed then that the computer still worked. There was brown, sticky apple juice residue on everything in the computer. There was even a puddle of this gooey gel that had pooled at the bottom of the case. It was all over the cables, the drives, everything. I was even more surprised and even a little bit proud that the computer still worked after that ordeal.
I guess that just goes to show: if you want a stable computer, get an Apple.
Those poor interns... (Score:5, Funny)
We would conspiciously watch from quite a few cubes away and watch this mice get whipped around in the air! It was the most hilarous thing we've ever seen! You'd think that they wouldn't buy it, but when push came to shove they did it and it worked for them after looking like fools!
Percussive Maintenance (Score:3, Interesting)
these darn web-savvy ghosts, nowadays (Score:4, Funny)
There's some spooky voodoo for ya, right there. They should probably call Ghostbusters, or something.
Threat of Violence (Score:3, Funny)
Super NoFriendo (Score:4, Interesting)
Finally it stopped working alltogether, but addicted to one of the games, I set to taking it apart and finding the problem. While it was apart, I found that if I held the game cartridge in with a certain amount of pressure it would work, but too much pressure or none at all and it would not operate at all.
Searching throughout the house for an appropriate weight, I ended up finding a 3 quarters empty bottle of Amaretto in the parental unit's liquor cabinet that worked perfectly. I spent the last semester of my senior year with a bottle of alcohol staring at me that I could never drink - for if I did my game console would die on me. It didn't last once summer started, though
Commodore copy protection madness (Score:3, Interesting)
As everyone knows, Commodore VIC-1541 Toaster is a very, very odd thing.
I once got a C64 game collection. The store was half across the country. Got home. Tried playing the games. A few didn't work. We mailed the games back to the store for replacement.
The games came back with a note "If the games do not work, turn the floppy drive to its side." With a helpful diagram.
Flipped the drive to its side, tried running the game, and wham - time to enjoy some games.
I later ran into some games that had such a weird copy protection that, in turn, didn't work while the drive was on its side...
Now, honest truth to tell, I've looked at modern attempts at DRM/copy protections with rather bleary eyes, but I think Starforce and the Sony XCP rootkits seem to have finally beaten this stuff - time to get worried about nasty copy protection schemes again...
Good old Windows NT 4.0 and HAL voodoo (Score:3, Interesting)
After a bit of digging I was finally able to determine that IRQ 9 was indeed being shared by more than just the tuner card and the video card; my ZIP Zoom card was also using IRQ 9.
For those who don't know what a Zip Zoom card was, it was a stripped down SCSI controller mainly used for external Zip SCSI drives.
After a few months of being unable to use both my Zip drive and tuner card at the same time, I grew weary of plugging/unplugging the cards based on when I wanted to use them and finally decided to do something about it.
The first step I took was to take a second look at the offending IRQ and changing it. The Zip zoom controller had a few jumpers you enabling you to change the port and IRQ. Finding out that the offending IRQ was 9 I thought it was a simple task at moving the IRQ jumper and therefore assigning a different IRQ.
I still get the same error. Move the jumper to its original position, same error. This is when things start to get weird. I keep moving the jumper between positions and NT still keeps saying it's using IRQ9. I boot into Linux and shuffle the jumpers back and forth and amazingly Linux says the IRQ for the card changes.
I then take a closer look at the card and its documentation and notice that the only IRQs the card supports are IRQ 5 and 7 (and NT reports it as having IRQ 9); I still remember the "hmm... this is odd" feeling I got when I found that out.
Long story short, it turns out that NT's HAL (Hardware Abstraction Layer) decided that my Zip Zoom card belonged best at IRQ 9 and assigned IRQ9 to it accordingly. I was then able to change the IRQ for the zip zoom card so that it used the a different IRQ than IRQ9; thus enabling my to finally use my Zip drive at the same time as my TV Tuner card.
This is what I call voodoo.
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Re:Current computer (Score:4, Informative)
some BIOS require certain devices to be present to pass the POST. I discovered this the hard way when setting up a headless server. I spent 20 hours installing gentoo, got the services all nicely configured and put the machine in the corner, and it never went online... so I pulled it out and brought it back to my desk and it booted fine.
I didn't find out that it was keyboard/monitor missing errors that was preventing the system from booting until I carried the monitor to the other side of the room and plugged it in and saw the keyboard error... then I poked around in the bios and saw the options for requiring keyboard and monitor.
Re:Current computer (Score:4, Interesting)
When they were on the third or fourth server, they realized the servers weren't booting up when they put them back in the rack. So they brought them back to the desk, booted them up and they worked fine. They'd put them back in the rack and nothing.
It took a couple of hours to figure out what the problem was. Somehow he'd managed to compile the kernel in a way that it wouldn't finish booting, if no keyboard was hooked up. He had no way to recompile the kernel there at the data center. He lives in Birmingham and the data center is in Atlanta, so going home to his own computer wasn't an option.
So he ended up buying a few dozen $5 keyboards at some computer shop and just laying them on top of the servers when they put them back in their racks. Worked like a charm.
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More seriously it probably depends where in the address range the bad memory is, Linux happens to hit something critical and Windows doesn't -- or vice versa on some other machine. In my experience Linux itself is more tolerant of bad memory than some of the apps -- gcc in particular. I started overclocking one box and
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