And taping the CD together would work?
I know CDFS is designed to be error resistant, but would that not be excessive, even if you lined it up perfectly?
I guess you couldn't lose half of it then...
Hello Friday! And hello also to On-Call, The Register's weekly reader-contributed tale of dirty data centre deeds done dirty cheap. This week, meet “Rick” who once worked for a non-government organisation as “both a software dev and part-time support-person.” One fine Friday afternoon, Rick “received a rather panicked call …
The person in the story had already demonstrated a very high level of muppetry by going back and trying to play the game again after nearly being rumbled. I reckon they'd be the sort who'd put the tape on the plain side of the disk so that the PC can still see the the data on the label side
"And taping the CD together would work?"
I've heard some tell a story of from back in the old days of thick ethernet cables where returning after a weekend they found the LAN performance was atrocious. After some investigation they discovered a workmap had been in over the weekend and had to move some stuff around but found a thick yellow cable in the way .... so he'd cut it, moved things past it then carefully soldered all the small wires in the cut ends together and taped up the join.
A neighbour once called me in becauser her TV reception was dreadful after an electrician had done some work in the attic. A precarious journey through the rafters revealed that the TV aerial cable had been cut and joined back together with a chocolate-block connector.
Some years ago our TV reception slowly deteriorated to the point we started losing channels. I suspected the aerial downlead was damaged, so joined a new length of co-ax to it and pulled it through. The old cable was chewed almost through at one point, where it ran through the roof space. Later that night I heard scrabbling noises in the ceiling, opened the bedroom window and shone a torch up under the eaves. The back half of a large rat was protruding, he was obviously enjoying a feast of the new co-ax. Next morning I fitted a balloon grating over the top of the rainwater downpipe to prevent him climbing up again, problem solved.
Back in the mid 90s, I had a hard drive die on me, when because of departmental miserliness there was no backup facility other than floppy discs. HDDs in those days had a ribbon cable (copper tracks on a flexible plastic strip, not individual wires joined by the insulation) going through the join of the two halves of the case. The fault turned out to be that the plastic strip had cracked, and broken several of the copper tracks. I fixed the strip back together with sticky tape and then used conductive paint to repair the tracks, and it worked long enough to back up all the critical data onto floppies.
"You've fixed the disc. Why do you need a new one?" was then the question from the purse holders.
...found a thick yellow cable in the way .... so he'd cut it...
Back in the day, a mate worked as an operator for a concern with a warehouse and IT suite out west of London and an office in the West End. They lost all the leased lines connecting the two simultaneously.
Turned out that a BT voice engineer had come across a set of fat cables that were "in the way" and not on his plans when working down a hole in the road somewhere between the two sites.
what it would take to keep two halves of a disk -intact- connected when spun up to 52x. speeds
A typical CD is only just able to hold itself together at those speeds IIRC. That's one of the reasons spin-speeds never exceeded that threshold. Some interesting clips did the rounds of people trying to spin them faster - They rarely ended well.
@Little Mouse : "A typical CD is only just able to hold itself together at those speeds IIRC."
Seemed unlikely to me. But Wikipedia says that as of 2004, the maximum speed of a CD was about 10400 RPM, or about 173 revolutions/second. For a 6-cm radius, that works out to a centrifugal acceleration (*) of about 7000 gees.
Now that I think about it... if it _wasn't_ close to the point of ripping things apart, it would make sense to try to get it to go faster.
(*) Yes, I know, there's "no such thing as centrifugal force." Sort of. You knew what I meant, though.
It's when they give up the ghost at 52x on first spin up in a quiet room on first that you really get a scare - a shattering disc makes quite a bang! I'm not sure what the previous borrower had done to the disc but clearly something had weakened it.
The library didn't charge me for it in the end, though it took me tipping the drive the disc had exploded in out on their desk and asking them where I needed to send the bill to waive the charge.
"I will admit to wondering what it would take to keep two halves of a disk -intact- connected when spun up to 52x. speeds."
"The only multimedia PC in the department" strongly implies that it was, at the very best, a 4x drive, more likely single or 2x speed. Your point still stands, although at single speed, a decent amount of gaffer tape should be good enough :-)
...there was an incident with a CD-ROM and sticky tape. Exactly as described. Even at the slow 4x speeds as was current back then, the disc came apart, the tape stuck to internal stuff while spinning and, well, I dunno what exactly happened but myself and the photocopy girl took the thing apart and that little plastic lens was nowhere to be found.
I used to enjoy playing around with lossy media such as CDs tapes and usenet, throwing more and more parity at it, and sometimes deliberately abuse the media to introduce more losses, just to see how much could be wrecked and still have a human viewable picture or audio left...
With that said, it would be interesting to see what a modified CD drive would be able to pull from a disc cracked and carefully put together again. Modified, because you'd want it to ignore luxuries like adressing and error correction/reporting and just get a raw bits (or probabilities of a bit or no bit) back..
I imagine it would be impossible to get the tracks aligned again, so it would in best case be randomly jumping to different track and getting stuck like a grammphone skipping tracks...
I wonder how well the metal layer is bonded to the rest of the disc, if a crack and would severely distort it on the rest of the disc too.
Years ago I had a Baldur's Gate CD that was out of kilter somehow, bad enough that when it spun up the side panels of my PC literally rattled. For two solid hours, my PC buzzed like Photonicinduction's playroom, but I was able to rip a clean image. Amazingly that poor abused CD-drive was still alive when DVD came around.
I still think one of the best abuses of equipment was my daughters primary school headmaster who, while the class were working quietly on something, proceeded to laminate various items. These include plastic knifes and forks, badge collections and other small items and only broke the classes concentration when he failed with a cup cake or muffin. It was hard to tell afterwards.
Just last year, in the school where I work, we had someone try to run an iron-on transfer page (meant for an inkjet) through one of the color laserjets. It made it's way into the fuser where it proceeded to completely wrap around the roller and gum it up completely. The fuser was a lost cause and had to be replaced.
Back on the subject of CD's: I once tried to spin up a very old (10+ years) game cd in a 52x drive for nostalgia's sake. It shattered into tiny pieces of plastic shrapnel inside the drive. I had to dismantle the drive to get it all out.
permanent markers on the whiteboards
I was in a meeting some years ago when someone was getting quite excited about the potential for the new product whose diagram was displayed on the wall. So excited, in fact, that he reached for a whiteboard marker to draw an explanatory line, only to look stunned by the yells of "No!!!, "Don't!!"
The diagram was being projected from someones laptop onto the projector screen that was pulled down in front of the whiteboard. Fortunately he did stop in time, although a little startled.
...because no-one carries another pen to scribble over that one or some hand sanitizer or (if this happens often enough) a small can of isopropyl alcohol.
I work for someone who used to keep permanent markers and dry erase (all black of course) in the same ziplock baggie. This invariably caused everyone to scream "be careful!" when a newbie needed to demonstrate something and was given the Bag o' Pens.
I asked once why the man didn't simply get a second ziplock baggie and separate the permanent pens from the dry erase. He looked at me like I was from Mars.
Then one day I turned up with a four color pen set, an eraser and some dry erase fluid* in a spritzer bottle.
"Where did you get those?" thundered the great man.
"Bought 'em" sezzeye.
"Where from?" he snarled.
"What, with your OWN money?" he spluttered incredulously.
"Yep. All ten bucks of it. Think what could be achieved with managerial levels of reimbursement. Non-black pens, erasers, a second baggie for the permanent pens. The possibilities are limitless." sezzeye.
This sort of conversation is why I don't get invited to meetings any more.
This bloke also has several whiteboards in his office but they are full of fossil writings and he won't let anyone erase them. I turned up one day with a Notepad folding whiteboard and my pens and he was so bewildered by my cunning Portable Visual Aid ploy he couldn't concentrate on the idea no matter how simple the drawing.
* irony abounds.
Once had a user who'd run out of the special (and expensive) laser printer acetates and decided to use some designed more for writing on with pens. One destroyed cartridge.
Then there were the (several) users who (several times) decided that putting partly-used sheets of labels back through the printer was a good idea, even after they destroyed the drum the previous time and had been told not to do it (again).
I'd forgotten the partly used labels, they'd sometimes unpeel from the drum and a bit of 1-1-1 Trich (yes, I remember when we could use it) would help.
I did ban one office from reusing paper in the fax machine after they put several sheets covered with Typex through Quite why they thought it a good idea to cover over the existing print and then use it again is beyond me, the cost of the new drum would have paid for a lot of paper. I guess that one wouldn't happen these days!
Ooooh - reused paper!!!
We had an accountant (well, of course) who liked to use the other side of previously printed on paper in his departmental DeskJet. It was all fun and games until he fed it a stack of pages that were stapled together. That took a bit of disentangling...
Does nobody fan paper before filling the paper tray anymore?
Years back there was a shared printer, Mopier, never had a jam after I filled it with paper (and fanned it well beforehand). Nice printer but was soon removed and scrapped because "it always jams", but nobody could understand why my printing was fine and of course nobody would listen since "there is no reason to fan it, that just wastes time"
"is there still an orientation [up/down] arrow on reams of A4??"
(And on the A3s too... ^_^...)
And yes, I know why the arrow is there, and yes, I fan the paper when I reload the tray. (Had an after-school job in a small copy shop / printer's in the early 1980ies, learned a couple of things that are still useful today. Also: Adobe PageMaker on the first Mac. 9" monochrome display. NO HDD, one FDD... so every couple of minutes you'd have to swap the data disk for the software disk for the data disk for the software disk for the data disk...)
Once had a user who'd run out of the special (and expensive) laser printer acetates and decided to use some designed more for writing on with pens. One destroyed cartridge.
I call either bollocks or ineptness. The film only enters the fuser unit after it has passed the drum so no, it won't melt there. The other possibility is loose toner by failing to adhere on the uncoated film. That will take perhaps 10-20 pages of dodgy printing to work itself. So, I could understand a gummed up fuser or rear rollers, but no, never a cartridge.
"...and now some part of me is desperately trying to imagine a glorious retro-future where laser printers were printing on celluloid transparencies..."
AKA the prank that's technically arson...
Way way back in my younger days as an ad agency copywriter (sometime in the very early '90s), I made the mistake of mentioning my hobby of working on PCs (or rather PC; being my personal one at home that I regularly upgraded and modded as needed for the purposes of gaming and such). Management saw this as a way of getting IT support without the hassle of actually hiring an IT person so somehow the job of regularly telling people to hit reboot; asking them if they actually turned their PC on when they complain that their machine is not doing anything; asking them if they turned the printer on when they complain that the printer is not doing anything; and refilling the ink tanks of the inkjet printer until the cartridges fell to pieces because management was too cheap to buy replacements, fell on me.
The printer was shared using a print sharing dongle which rarely worked properly. More often than not it was easier to copy the file to stiffy and take it to the accounting department where the kind bookkeeping lady, who had a dedicated printer, would print the files out.
My favourite was the company's network, called FrisbeeNet because it consisted of copying files to a stiffy disk and hurling it across the room to the recipient.
"More often than not it was easier to copy the file to stiffy and take it to the accounting department "
Did you give the nice lady in accounting your stiffy? Uh.. huh huh huh huh. :-)
I've heard of being a shower rather than a grower, but South Africans may be the only people I've heard of who can have a 5.25" floppy but only a 3.5" stiffy.
I had a DVD shatter in my drive(*) and it went into so many small pieces the only way to deal with it was to take the drive out of the computer and then dismantle the drive case as well to get the pieces out. I gave up counting them when I reached 30.
(*) It had a small crack when it arrived, I'd hoped to be lucky enough to read the data once before binning it. Lost the gamble.
You were lucky.
I had a game on CD-ROM once called "Grand Prix Manager", and I loved playing that game. So much so I continued to play it even though cracks started to appear in the centre of the CD. One night time, about 1am when I should've been in bed asleep, while playing the game there was an almighty bang and the CD-ROM drive stopped spinning. I look at it, press the eject button - nothing.
Queue woken parents walking in to my room asking what the bang was. I said I fell out of bed.
The next day I took the CD-ROM out, and the CD was in pieces of various sizes which had done enough damage to the CD-ROM drive to warrant a new one.
At least it was lightweight modern media.
The comp sci dept in my University kept as a relic and never fixed all the years I was there the fragments from a drive off an old VAX or IBM clone (not sure which one - we had both) embedded in the door.
Some idiot during one of the many repairs throughout the hungry post-fall-of-wall years disabled the safety on the drive case. Another idiot tried to open it while it was spinning at full throttle. Both got very lucky after the drive disintegrated - the frags were embedded all the way through a 1 inch thick wooden door and sticking on the outside. There was quite a bit of damage around the server room too. But somehow, miraculously, the idiot whoddunit was unscathed. There is a slavic proverb: "God looks after the drunks, little kids and the feeble of mind". Definitely applies in this case.
High speed drives (52x) had a habit of shattering disks, usually blanks being written because they were that bit thinner I guess.
More a than a few times bits of the disks were embedded within components within the case or had completely destroyed the inners of the drive. Quite scary how much energy could be put into those little disks.
ALWAYS limit the speed via software (under Linux "eject -x N" where N is max speed). I once computed the kinetic energy of a CD when spinning at 48. While I do not recall the figure, it was certainly big enough to explain the "bang and drive destruction".
Does somebody recall those funny shaped CDs often given away as gifts? Some of these were sure to disintegrate at any of the higher speeds. I watched one tower PC do a dance because the CD (such a funny shaped one) had a center of mass that was way out of it's mid point. Miraculously, everything survived.
"a significant %age of the speed of sound"
That is highly contingent on how you define "significant", seeing as how one is 340m/s and the other is 65m/s - 19% certainly sounds significant as odds of winning the lottery but decidedly less so as a task completion ratio when your boss asks. Not that it should matter all that much past its trivia value - barring some boundary layer weirdness, the mach number of objects moving in air should be much more important when they actually move through it than when they continue occupying the exact same fixed volume...
"Curiously, when Mythbusters had a go at this the only way they could persuade a CD to shatter was with a modified angle grinder to spin it up."
That was the very first episode I ever watched, and it put me off the show for years. Eventually I accepted (my wife helped a lot) the idea that, as in the more typical sciences, some proven experiments simply don't like being reliably reproduced.
"Clearly something has changed in the manufacture of discs over the years."
Billions upon billions have been produced. Some will have invisible flaws that got through whatever level of quality may or may not exist in the various plants. Then they get used and abused by users.
Having said that, I was doing field break/fix when CD drives arrived on the mass market right through to 52x models arriving, including for a couple of retail suppliers so home visits involved, and never saw the results of an exploded CD/DVD.
Yeah, I saw the same episode. What they missed was they were using new, undamaged CDs. If even the smallest crack appears at the center hole, the stress at over 48x will break the CD.
For a VERY short time, 90x drives were available (2001 or so) and these had such issues that fragments of disks would some out the side of the PC case.
I worked in the past for an organic fruit company, and we occasionally had people bring in their eyeMacs, having tried to insert their SDCard into the reader, but misjudged and place said SD card into the slot loading DVD drive instead.
One does not simply turn the eyeMac onto it's side and "give it a shake!"
My son took an interest in my Macbook when he was much younger and one day the occasionally used slot loader stopped loading discs - it would only take them in so far and I knew pressing any harder was not going to help. One nightshift I finally decided to do the 30 to 40 step strip down and ultimately found an old car tax disc had been inserted and then crumpled itself nicely in the drive.
I removed it, reassembled and all has been OK since.
My son no longer inserts things in the slot....
"One does not simply turn the eyeMac onto it's side and "give it a shake!" "
Yes, one does. The trick is to make sure you do it out of sight of the customer and to keep shaking until the card falls out.
The alternative was a chargeable repair to dismantle the machine and extract the card.
I dont trust CD's and DVD's in a PC in the slightest.
On more than one occasion I've had them spin up and shatter in the drive, turning them into high speed shrapnel that fires out of the front of the machine fortunately narrowly missing me but on one such hitting someone behind me in the back of the head.
Deeply glad they are dying out in favour of flash storage and cloud.
We had some PCs a while back with slimline optical drives. Due to some oddity of the design, it was possible for a suitably skilled user to insert the disk in such a way that it disappeared into the PC case. Some users were particularly good at this. Not that they mentioned it when the first or second disk vanished, of course...
I recall an old episode of Mythbusters, where they set up a rig to cause a CD to shatter (the myth being tested was something like a guy had been killed when a shard burst out of the computer casing and went into his jugular).
They built a rig using an industrial-grade power tool as spin the disk. It took quite a few refinements and upgrades before they got results - the RPM count was crazily high. The disk was surprisingly resilient but when it finally went....wow, did it go!
> wow, did it go!
Friend of a friend had the bright idea to put a record, not vinyl, but a good old shellack one, on the pulley of a motor that he had stripped off a vacuum cleaner. He did it in the attic. The record disintegrated as planned. That the fragments gut stuck deeply in the wooden beams of the attic, perpendicular to the fibres of the wood, came as a surprise.
That not a single piece hit him: sheer luck.
"That not a single piece hit him: sheer luck."
Well, that, or the basic common sense reflex of never, ever standing directly in the plane of any speedily rotating object regardless of which power tool is spinning it. In some fields (such as ones involving lathes and chuck keys*) this is outright a baseline Darwin Award selector - or so I hear.
* One can always recognize a properly indoctrinated Pro from his springless chuck key - while it's meant to prevent exactly that sort of orbital shenanigans, people seem to find the presence of said spring bothersome for precision four-jaw centering...
Back in the 16-bit days, the only form of portable media (in fact, pretty much the old media for the Atari ST and Amiga) was ye olde 3.5" floppy disc. And as impoverished teenagers and students, we tended to use the cheapest of the cheap. Magazine coverdisks were one source - I can recall people selling bin-liners full of these at markets and car-boot sales - but if you were feeling flush, you'd fork out the cash for a box of no-name disks from some far-eastern company you'd never heard of before [*].
Needless to say, quality control was an issue; aside from the usual plethora of read/writing issues, you'd often get issues with the protective plate not sliding open, or the disk failing to spin correctly inside it's sleeve. The best one I ever saw was when a friend enthusiastically hit the eject button on his Amiga, causing the disk to shoot out at a higher speed than normal; said disk literally disintegrated in flight, like an armour-piercing SABOT round...
[*] Much the same happened with the earlier 8-bit machines (magazine cover-tapes and no-name C90s - generally, the quality of the no-name cassettes was so low you could barely record audio on them, never mind the squeaks and squeals of a computer program. And then there were the budget VHS tapes as well; good luck watching anything you'd recorded on these, especially if you'd optimistically gone for LP recording; twice the duration and a quarter of the quality! Admittedly, budget CDs and DVDs were just as bad; there's nothing quite like picking up an old backup to find the aluminium peeling off...
When I upgraded to a (very cheap, unbranded) 52x drive from a 6x drive I felt chuffed - up until the point I ejected the disc. It was still spinning at - I suspect - 52x speed. Thought it was goingto take my bloody head off, and the disc was definitely not readable after breaking against the wall.
Many many years ago I worked for a media company and one of my jobs was to produce presentation DVD's. We had a 15 disk replicator, 32x, that was rather expensive.
Having been volunteered the task of replicating the master disk, I duly cracked open a batch of fresh blank disks, placed them in their trays, we had white gloves to avoid finger prints, and hit the start button, within five minutes all but three exploded in a series of loud rapid fire bangs. The poor video editor, behind whom the replicator was located, was very pale as one of the fragments had embedded itself in the cork-board behind his monitors. He promptly when outside and smoked 10 cigs in a row.
The replicator was dead as well as a few nerves. The rest of that batch of disks were binned and I let the video editor explain to the supplier why we wanted a full refund plus a new machine. He was very explicit in his reasoning.
Why they didn't invent a CD drive that read the disks by essentially photocopying them.<br>Use the read laser like a copy machine's reader, scan the disk, create an ISO of the "image", & then spit out the disk once done.<br>That way you then have a copy of the disk, can mount it as if it were a floppy, & store the image for later reuse.<br>But then I realize I had answered my own question as to why NOT, because then we'd all become "filthy pirates" trading ISO's amongst ourselves, friends, family, coworkers, etc, & the sales of disks would flush itself down the toilet.<br>But I thought the fact that the disk never needed spinning up meant that it would be safer from a kinetic energy remaining as inertia to be launched as shrapnel point of view; it would mean the laser would move but only once per disk, which would mean it could take about the same time to read the disk but do an infinitely better job of it; & our original disks would last far longer from the lack of constant abuse.<br>Manufacturer's could then save money using a grade of media that would otherwise have been insufficient for a spinning drive, since the drive didn't spin anything & it (the disk) only needed to handle being fat fingered by whomever slipped it in the drive.<br>Man, I wish I didn't have these crazy ideas, they make me wonder why they were never made real...<br>Someone hand me my frog pills, I feel another fit coming on.
I can't even imagine how that would work.
If the media isn't intended to be spun (i.e. it was to be raster scanned) it'd be better *not* to have circular tracks since you'd lose resolution through aliasing (the track pattern not matching the scan pattern) and need a better laser, and you'd effectively have to scan the whole disc into a *horrendously* large image file before you could reconstruct the contents of the circular tracks.
If the tracks were to be arranged to suit the raster scan- in which case it'd be better for it to be square than disc-shaped anyway- you'd have to switch direction back and forth incredibly fast for each new row to match the speed of a CD reader, unless you had multiple heads. That would increase the mechanical complexity, be hard to implement reliably and would be pointless in general.
Using a spinning disc means you can have an almost fixed head- only needing to move outwards *very* slowly (relatively speaking) to follow the spiral- but still have the track moving at high speed while being effectively endless (until it reaches the actual end) so no need to abruptly move the head. It's mechanically by far the most sensible way to do it.
Your idea is... "interesting". ;-)
Why they didn't invent a CD drive that read the disks by essentially photocopying them.
Someone once did an experiment to "digitize" records (the round, usually-black, made from vinyl kind) on a flatbed scanner. An interesting but ultimately not very effective method. Some historical archives are doing something similar, using an optical reader, but it follows the spiral of the record track. Useful for those old broken acetates that could never be played by conventional means. By no means fast either.
In theory, yes. If the printer's resolution is up to it.
I must admit, this would be a cool thing to do with a 3D printer that uses metal dust as a medium.
Just imagine - Ace of Spades on a metal 7"...
(Not sure about how the record player's needle would handle this, but what the hell.)
There were projects to build record players for vinyl discs that didn't use a needle but a laser beam to read the grooves in the disc, then process the scan data into sound. Made it past proof of concept and into the prototype stage, IIRC - but eventually were cancelled because nobody saw any real money in it. But that was before vinyl got hip again, so maybe someone will give it another go.
ELP has a consumer line of laser record-players. they're "only" $4000 - $15,000 (down from $25,000). The advantage is that it has no needle to ever replace and shouldn't wear records down. The problem is that it's vastly more expense for no gain in quality. I've read that it sounds fine, but not nearly fine enough for audiophiles to fork over the big bucks.
I've read of a similar system using an ultrasonic beam which is far cheaper and also sounds decent.
I've selected the Paris Hilton icon since she's a famous DJ now, hah!
bearing the largest toolbox we had
Ah yes, I've done that trick one or twice over the years. Anyone properly equipped to work on the early Macs would have had a particularly serious looking T15 Torx with a shaft at least 9" long - waved around in the right manner, you could properly intimidate a user with one of those :-)
Of course, at the other extreme, you make fairly "industrial" tasks look really delicate (and so make your skills look better than they actually are) by the correct choice of very small tools held in the right manner.
A single-speed cd spins at 200-500 RPM (depending on where it's being read)
52x that is 10,400 RPM, at slowest.
120mm across. (or 0.12 meters) x 3.14 (pi) = 380 CM circumference (.38 meters)
.38 X 10,400 = 3952 meters/minute/60=65 Meters a second. X2.5 to give us full speed. 164 M/Sec
164 m/sec = about 360 MPH, outer rim speed. Slightly less than half the speed of sound.
Yep. They're moving.
I think of all the stupid stuff I've come across, five part line printer paper has to take the McVitties Digestive.
In order to get the fifth part to show anything at all you had to crank up the hammer velocity to such levels the first two parts were often turned into confetti as the letters were drilled through the paper.
Then there was the time I worked a Unisys contract and a fellow consultant sent ten copies of a monster report to the only available line printer. I waited for two hours to use the printer then asked what was printing.
When I found out I asked why ten @SYMs had been sent. When the requestor had explained, I asked "why not send it as three three-part prints and a single-part?" the requestor's eyes widened in horror. Others around me were asking "what is three part when it is at home?"
This is what happens when the programmers know nowt about the hardware.
Philips did a demo (I thought it was shown on Tomorrow's World, but I can't find it) where a CD had four slots cut into it at 3, 6, 9 and 12 o'clock positions and it played perfectly! Now that might have been becasues CDs play from the inside out and it never got to the slots...
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