Dan's Data letters #73
Publication date: 13 November 2003.Last modified 15-Aug-2012.
Wanted: Free stuff
I am a college student in India, where new laptops are bloody expensive. I am pretty sure that somewhere in the world there are people who have old laptops (P-II, P-III) gathering dust in their closets. I would be pretty happy to get my hands on a reasonably fast machine for low cash or even better, for free (excluding shipping of course). I would define "reasonably fast" as a minimum of a P-II 366, 128Mb RAM, 6Gb HDD, CD-ROM, network adapter and modem.
Are there organizations which recycle old PCs and laptops to people like me?
Aditya
Answer:
Yes, indeed there are such organisations. One of them's called "eBay".
Actual free computer hardware is pretty much restricted to seriously elderly gear; a medium-old laptop like the one you describe can still command a price of at least a couple of hundred US bucks on eBay, so you won't find a whole lot of people giving them away.
This, of course, presents a problem for you; I'm figuring that since the average wage for skilled IT workers in India stands at maybe $US8500 a year, Indian college students probably don't have a whole heap of buying power.
There are ways and means, though.
Buy a laptop with a busted screen and keyboard, and another laptop with nothing working but the screen and keyboard, and you're in business, for instance. A laptop with a broken internal pointing device could also be had cheaply; I've got a ThinkPad like that. It needs a whole new system board if I want the TrackPoint to work again, and I wouldn't want to swap the board in even if I could get one for free. Solution: Just plug in a darn mouse, and get used to canceling the error messages you get when you cold-boot the thing.
Cheap laptops can often be money holes, especially if you need to buy a battery (which'll never be cheap, though batteries that use standard 4/3A cells can be re-celled by anyone who can solder and owns a small hacksaw and some epoxy...) or more memory (also not cheap, and there are often nasty incompatibility issues which you may only discover when your "PC133/PC100" RAM does not actually work in a laptop that very definitely requires PC100 only SODIMMs).
If you do your research, though, it is possible to get a reasonable portable for a good price.
Linux users can have an advantage here, as old Pentium-class machines are likely to be more than fast enough for them.
Curse the brightness
I recently purchased an IBM P260 21" (refurbished) monitor (eBay, of course). The problem is that it's too bright. Even with the Brightness set to zero, "black" areas are gray. I can turn down the gamma (I have a GeForce3 Ti200), but it's still bright.
I've opened the case and searched for an obvious brightness control (Brightness, Screen, whichever) with no luck. There are a bunch of knobs with enormously helpful labels like APH, XCV, XBV, H. TRP, CBH... etc. They seem to control aspects of the screen focus. The flyback transformer (I have put some research into this) has two Focus controls, but nothing else. The neck of the CRT has some tabbed rings that (like the knobs were) are held in place by a thin strip of something, and I'm fairly certain that I don't want to mess with those.
So, is there something that I've missed? Is my only option to run the monitor for a few years and wait for it to dim?
Neal
Answer:
I'm not a CRT repair expert, and I don't have a service manual for the P260,
but there should indeed be internal adjustments with which you can fix this.
[Insert standard CRTs Can Kill You Stone Dead Even When They're Not Plugged In warning here. It is tempting to play with settings like these while the monitor is powered up; I will not be held responsible for any of the several hilariously lethal things that can happen as a result of this. Please, at least, work with one hand behind your back.]
There should be a little gain potentiometer for each of the three electron guns; adjusting the gain down evenly for each ought to cure the problem (adjusting them unevenly lets you correct for colour casts beyond the capabilities of the standard colour balance adjustment). There may also be an overall gain setting; I don't know. You'd need a service manual to be sure.
It's also conceivable that the cathode heater filaments are being driven too hard. Usually, old CRTs have underdriven (or just plain worn out) filaments; it's possible that the "refurbishment" this monitor's had included some tech winding the filament voltage way up to give a nice bright picture, at the cost of tube life and contrast ratio. The tube filaments should glow quite brightly orange-yellow, though; it's harder to spot an overdriven filament than an underdriven (red) one.
For a lot more information, you may find the Sci.Electronics.Repair FAQ's section on CRTs helpful, or at least interesting.
Cheap DSLR alternative?
I enjoy photography but I am poor. I have a £200 digicam but it doesn't do the things that an SLR can manage. I could use my dad's film SLR, but with developing costs at £8 a go this is still too expensive. I thought it might be cheaper if I could find a company that will transfer photos to a picture CD and not bother with prints. I haven't been able to find such a company.
Idea number 2 was to develop the negatives myself and use a film scanner to transfer the images to my PC. Does this sound feasible idea to you? Will the film scanner be worth the investment?
Lee
Answer:
Call your local minilab and ask where you can get images transferred to
Kodak
Photo CD (not "picture CD", that's Kodak's brand name for the more recent
1536 by 1024 pixel consumer variant). Photo CD's top resolution is 3072
by 2048; there's a fancy Pro Photo CD that goes up to 6144 by 4096, but
you're unlikely to find a place that'll make those for you cheaply, and
you probably don't have that much real detail in most of your pictures anyway.
Photo CD pricing and image quality varies depending on who's making the discs for you, but you shouldn't expect to get away for much less than $US1 per image. This is very cheap compared with traditional imaging bureau services, but very expensive compared with fully digital photography.
Your second idea is, I think, only a good one if you really enjoy developing film.
If you're not doing a whole lot of photography then it could work, or you could save some time by taking the middle road - have the film developed at a minilab, and then scan the negatives yourself.
You'll have to pay pretty big bucks to get a scanner as good as the Photo CD people ought to be using (they may not be using the big old drum scanner that they ought to, mind you, and their scanner operator may or may not have a clue...), though, so I don't think this looks like a great solution whichever way you slice it.
Personally, I'd just use my cheap digicam for now ("it's not the camera, it's the photographer"...) and put money aside for a DSLR, rather than spend it on film, developing and so on.
Canon's recently released EOS 300D has a list price of only $US999 including a decent lens, and there are some bargains to be had in the second hand DSLR market too, though these things seem to hold their value pretty well.
Cooler compatibility
I'm trying to replace a dead Socket 7 CPU cooler on an old ghetto box. Can you tell me if a Socket 370 heatsink/fan will fit Socket 7 without fighting the clip?
Steve
Answer:
Yes, it will. Socket A coolers should also work. All three sockets have
the same basic external dimensions and cooler mounting hooks - well, the
middle ones at least.
Socket 7 CPUs are taller than Socket 370 ones, though, so a Socket 370/Socket A cooler may be unacceptably tight if you use it on an old processor. This is unlikely to be dangerous, but it could make it hard to attach and remove the cooler. In extreme cases, you might manage to rip a hook off the socket, which is Bad.
Busted burner
I have an older model portable CDRW drive that, as far as I can tell, the drive itself went out on. What are the chances that I can throw another drive in there with pleasing results? Any real worry that it will fry whatever I throw in?
Matthew
Answer:
If you're talking about a chunky box containing a normal 5.25 inch drive
mechanism, and if that mechanism is IDE, then there's an decent chance that
a current off-the-shelf IDE CD burner will work fine. Don't count on being
able to write discs any faster than you could before (if it's a USB1.1 device,
for instance, there's no point trying to burn faster than 4X), but yes,
it ought to work. It may require the drive to be set to Master; it may not
care.
If it's got a SCSI drive in it, then it also ought to be OK, but you won't be able to find a new SCSI burner for cheap. Second hand could be an idea.
If the external box is a slimline unit that doesn't contain a normal drive, though, then it's now a paperweight.
Baby's first AVI
Is the video resolution of the Mustek DV3000 too crappy to watch as a normal video on VCD?
I was thinking of getting one, but NOT if my wife will bitch about only seeing our son's every second step!
Ben
Answer:
The DV3000's resolution's not great, and the frame rate is low, too. VCD
conversion would, of course, require recompression of the video (from MJPEG
to MPEG), but you probably wouldn't lose any noticeable extra quality from
that.
I wouldn't use a DV3000 to record anything important, unless its other qualities (cheapness, lightness, vibration-proofness) make it more suitable than alternative systems. It's a brilliant gadget for the money, but it's certainly not up there with a proper camcorder for quality
You'd probably be a lot happier with a humble old second hand Hi8 camcorder and a video capture card. That'd be somewhat more expensive and involve more work, but it'd give a much nicer result.
Switch solution?
I have one of the original Book PCs, and the power switch went bad. I have to hold it down - pressed in - for the power to stay off. If I release it, then it powers right back up again.
Is there a way to purchase a replacement power switch?
Patricia
Answer:
It sounds as if you've got a switch-bounce issue - the switch is "chattering"
a few times after you release it, and that's turning the computer back on.
Modern ATX power switches are momentary; all they do is short the two power-on
pins on the motherboard each time you press them.
If this is the problem - actually, if it's any problem that requires replacing the switch - then there are a number of possible solutions. I doubt you'll be able to find an official Book PC Replacement Power Switch, but the switch itself will be a simple little momentary pushbutton mechanism, and there are a zillion of those in any decent electronics store. You may be able to find one that you can fairly easily swap in.
Alternatively, some other switch could be connected to the current switch's cable and used instead. Any momentary switch will do, and no dangerous voltages are carried on the wires. So if you don't care about a somewhat Mad Max appearance for the computer, you can just rip out the old switch, run the wire through the hole and stick the new switch in the hole, or to the side of the case with double sided tape, or just leave it dangling.
Anything that shorts the appropriate two pins for a moment will do, here. It's possible to turn a bare motherboard on and off with a car key, and many computer technicians do.
(A reader's also pointed out to me that a simple solution to a dud power switch is to unplug it, unplug the reset switch as well, and plug the reset switch cable onto the power switch pins. Bingo; problem solved. You can't easily hard-reset the computer any more, but wouldn't you rather be able to turn it on and off?)
Magnets: Why?
In Letters #72 you gave a link to Forcefield's site, where they sell large cylinder magnets. While they were quite impressive in size, and certainly cheaper than I expected, it mystifies me what such magnets are used for. What sort of applications need Excitingly Large Magnetic Fields?
Michael
Answer:
Well, there are various scientific applications for them (if you need an
electron beam bent the same way every time, a permanent magnet or two could
be what you're after), and there's always the old junk-fishing idea (attach
magnet to string, throw into lake, reflect on the fact that the most interesting
thing you're likely to find is a rusty pistol used to kill someone in 1972),
and then there's the time-honoured Just Mucking Around sort of applications
(and, of course, quackery),
but many people who buy them are making electric generators. Forcefield's
sister site, otherpower.com, has
a bunch of
examples.
Magnets: Here's why!
Inspired by your ramblings about rare earth magnets I decided to dissect an old 540Mb hard drive to get the magnets out. Even though the magnets are only about 2 square centimetres and fairly thin, I'm amazed how strong they are. I've been playing with them and found lots of cool things to do with them, though most not very useful.
One practical use I found was to put one in my pocket and stick remote controls for the TV or whatever to the outside of my pants. Even a remote with AAA batteries sticks well enough to get up, walk around and shake your leg without it crashing to the floor.
Immediately after this discovery, ideas flooded into my head of couches with built in magnets for this purpose.
Would holding remotes like this reduce battery life at all? My guess is no, that the magnet is attracting the metal casing on the battery and doesn't affect the internals at all.
Do you think sticking remotes to the couch or pants is cool, or is the coolness limited to my world?
Tim
Answer:
Batteries, and most other electronics, don't particularly care about static
or slowly-changing incident magnetic fields. You might be able to get a
remote control to misbehave by spinning a big NIB magnet near it; that'd
induce a voltage in various tracks on the circuit board. Since there's no
sensitive RF or other very-low-voltage circuitry in there, though, I doubt
any domestically achievable magnetic field could have any effect at all.
You'd be physically pulling ferromagnetic components out of place (starting
with the batteries) before any other effects showed up.
And yes, I do think this is a cool idea! You've got to remember to put the remotes in the magnet-equipped spot, of course, but I don't think it'd be too hard to set this up, provided you can just unzip the couch cover to place the magnet. Tape would do to hold it in place.
I may do this myself!
May I take your coat(ing)?
Thought you might like some feedback on a successful method to remove a damaged/faulty monitor screen coating.
Without any help from me or my family, the coating on my computer monitor screen, a Mitsubishi DV17NF, started to deteriorate. At first, it was barely noticeable, just a few very tiny bright specks here and there over the screen's surface. As time progressed though, the specks grew into larger blobs and even the gentlest attempts at cleaning the screen with a soft damp cloth (as recommended in the manual) caused even more of the coating to come off, in jagged streaks resembling scratches all over the screen.
In the end, the coating on my monitor screen became so deteriorated that I had to make a decision about what to do. I tried contacting various glass coating businesses, even a couple of specialists at universities and last but not least, some scientists at the CSIRO who also specialise in optical coatings. Unfortunately, no-one from any of these organisations was able to offer any real help. In fact, the common thread between all of their advice was that anti-glare/UV type filter coatings are generally so robust as to defy practically all attempts to remove them.
It seems that all good quality coatings are applied with a kind of Electro-Plasma process under very precisely controlled conditions, which causes the coating to be deposited in such a way as to create a molecular bond between the glass and the coating compound. The resulting surface is then supposed to be at least as hard as the parent glass and therefore very durable. It would seem then, that if I could have had this supporting information at the outset of the coating starting to deteriorate, and have been knowledgeable enough to know where to look for it at the time, I could probably have had the monitor replaced under warranty due to the presence of a faulty screen coating with supporting evidence from scientists from the CSIRO no less.
Anyway, we all learn by our mistakes. Subsequent to this, I returned back to some previous advice offered by a friend. His suggestion to use a good quality automotive cutting compound to "polish" the coating away - and it worked like a treat! Lo and behold, the coating came off the screen as easy as pie and after a clean-up with a damp soapy cloth and a soft dry cloth, the screen looks as good as new.
I don't know that I even need to worry about getting hold of an anti-glare screen to hang over the front, as the small room that I use as my home office-cum-hobby room has no natural light source, only artificial light from a small ceiling mounted fluoro. As a result, there is no glare worth worrying about.
Maybe this experience of mine will help others who find themselves in a similar plight. I guess the only additional expense is for the purchase of a good quality anti-glare filter to hang over the front if glare proves to be a problem. I've been able to track down a few different styles of these and the better ones seem to cost around AUD$90 - 100. A lot less than the purchase of a brand new high quality monitor.
Mal
Answer:
I've mentioned buffing off monitor coatings
before, but I spoke from zero actual
experience. It's good to hear from someone who's actually done it!
