Dan's Data letters #55
Publication date: August 2003.Last modified 09-Jun-2013.
RAM power
I am considering getting a Powerbook G4 in the nearish future, and it contains two memory module slots. Now, I have always been told that more memory means more power drain which means less time available on the battery's charge.
That being said, which is going to drain more power, a single 512mb module or two 256mb modules (or, just for grins, two 512mb modules)? And just how much does memory drain the laptop batteries?
Ed
Answer:
Yes, RAM uses power, but not enough to be worth worrying about. Compared
with the power that's needed to run the processor (and supporting system
board electronics) and the display, and the hard drive, the power drawn
by memory is negligible. Also, if adding more RAM means you're flogging
the hard drive less, that may well cancel out the difference.
CD and DVD drives, by the way, are also quite big power-suckers when they're spinning - especially if the disc's unbalanced.
The exact power drawn by a memory module (with a given access pattern) depends on the chips it's using. It's possible that a new 512Mb module will draw less power than a single old 256Mb one. In any case, though, you're not talking enough wattage to worry about.
Tonight, on "You're Boned"...
I have a 19" flat screen monitor, with anti-glare coating. It's been mine for over a year and a half now, and everything was fine with it until I moved two weeks ago. Somehow a small scratch found it's way smack-dab in the middle of said screen. The crack is hair thin, absolutely invisible when the monitor is turned off, but creates a whisker-thin rainbow of colours when anything other than black is displayed behind it.
I thought to myself "Meh, after a week I won't even notice it anymore", but I had underestimated its quite CENTRAL position in my field of view. Do you know of any method or product that would help me either get rid of the scratch or fill it as to make it vanish without destroying the anti-glare properties of the glass?
Yvan
Answer:
Nothing short of buffing off the whole front of the monitor, leaving it
coating-less (and creating lovely leaded glass dust!) is likely to do any
good.
I talked about this in this letters column; conceivably, some kind of similar-refractive-index wax might help, if the scratch is fine enough, but I wouldn't pin my hopes on it.
For lenses you're looking through - not eyeglass lenses, so much, but camera and telescope objectives - you can fill scratches with something black and cause their effects to largely disappear. For things you're looking at, though, this only makes the scratch more visible, to many people's dismay.
Road to nowhere
Although we all know you are omniscient when comes to things IT, I felt I should send this link to you; it's a new hard drive cooler by Zalman. Even though it has no moving parts, it does look really neat.
I hope they send it to you soon for your review.
Matthew
Answer:
Yes, it looks cool, but this a device with heat pipes that don't go to a
heat sink. The pipes just connect one side of the drive to the other. If
a heat pipe is warm at both ends, and not cooled in the middle, it isn't
likely to do anything.
But what do I know? I haven't reviewed one. HardwareZoom have, and they say it did a great job of cooling a 15,000RPM SCSI drive. Bit-Tech more or less agree.
(A reader's also pointed out that Zalman seem to be planning a whole case replete with heat pipes. And another reader's told me that he doesn't care whether it works on a hard drive or not, because where else can he get ten heat pipes to experiment with for less than 35 Euros?!)
Portable patrol
I'm going back to college in a few weeks, and I have about 1200 Canadian dollars to spend on a laptop. With so many choices out there, I'm a little lost. Are there any particular brands that you would recommend or caution against? I'm really just looking for something I can play some decent games on and fire off the odd assignment from.
Shawn
Answer:
For that kind of money, you're not going to get anything nice new. You can,
however, buy a good used machine. I'm not a laptop expert, but I like IBM
ThinkPads. Not too bizarre hardware-wise (install WinXP on a vaguely recent
ThinkPad and everything Just Works; no goofy extra drivers are needed),
very solid, reasonably light, and both whole laptops and replacement parts
are commonly available on the auction sites for good prices. Also, most
IBM laptops are actually made by IBM; most laptop manufacturers are just
rebadging a
generic product.
ThinkPads are still laptops, though, so there's proprietary hardware and other oddities, like the marvelous One RAM Speed Only, Thank You problem that means that a ThinkPad 600X (for instance) will only recognise PC100 memory; PC66 memory won't even be noticed, and PC133 memory will stop the ThinkPad from booting until you remove it. But ThinkPads are so popular that a Google Groups search (or, as a reader's now pointed out, a search of the ThinkPad Mailing List Archive) will answer most technical questions you have. IBM have a decent support site too.
If you want a fast 3D graphics adapter for $CDN1200, you're in trouble. You might be able to find some nasty Chinese notebook with a GeForce2 Go or something for that kind of money, but if I were you, I wouldn't bother trying.
2D games are another matter; lots of old hardware is A-OK for Starcraft and Worms Armageddon!
If you want a laptop for practical purposes, expect to spend two thirds of your budget on a ThinkPad 600E or 600X ("adequate" and "quite nice" for Win2000/XP, respectively, with something like the maximum (288Mb) RAM in the 600E and a similar amount in the 600X; both are more than good enough for Win98 with 192Mb RAM) from a well-feedbacked eBay dealer. If you really just want to play 3D games, though, give up on the laptop idea; save your money for a normal PC. If you get a small form factor PC with an AGP slot, and an LCD monitor, you'll still have a highly portable system, but you'll also have reasonable 3D frame rates.
Old-school video
I'd like to revisit my old Apple ][ and take a drive down 8-bit memory lane. I started in 6502 assembler in about 1979, when I was about 13 or 14 years old. Actually, my real start was on a Z80 on a TRS-80. I would ride my bicycle five miles to the Radio Shack and sit in front of the machine learning BASIC. But I digress.
How can I connect my old Apple to my current monitor? I need a composite to DB15 converter I assume. Would this work?
Mike
Answer:
No, it wouldn't, because it goes the wrong way - it lets you turn a "VGA" signal into composite or
S-Video Y/C, not the other way around. What you need is a composite-to-VGA adapter box that
can do scan-rate
conversion.
You need the conversion because modern monitors can't sync to the 15-point-something kilohertz of all composite video, including the Apple's output, even if it were an RGB signal rather than composite, which it isn't.
So you want a composite to VGA box, as used to connect game consoles and VCRs to PC monitors. Expect to pay $US50 or so for a half-decent one.
If you get a TV tuner card for your PC that has composite input, or if your video card has composite input, then that'll let you view Apple II output on your modern monitor, too - provided your PC is turned on, of course.
Cable hacking
I'm looking at doing something about those ugly yellow, black and red power cables currently obstructing my view through the window of my Antec Lanboy case. Cable sleeving seems to be on its way in and this I will attempt. My question to you is - what can I do about the unrequired cables? My new computer is a forbidden zone for floppy drives and I'm not about to take a step back in technology with my mobo, so those old power connectors are just messing up the case.
Can I detach the unwanted cables from the PSU or can I at least shorten them without causing the usual un/due hassles (amount of hassles dependent on current karma levels).
Gary
Answer:
Yes, you can just snip the unwanted cables off (preferably when the PSU's
not plugged in...), wherever along their length you like. If you leave no
dangling copper then there'll be very little risk of shorts-to-chassis happening,
but you can reduce that risk to zero by insulating the ends - paint-on "liquid
electrical tape" is excellent for this, or you could use little caps of
heat-shrink tubing.
Seeing as you may find yourself needing at least some of the extra cables at some point, though (a PC with a high end Radeon in it, plus one of several models of FireWire card, but no floppy drive, can still need two floppy drive plugs...), you might like to consider just neatly bundling them all up at the top of the case. You can get stick-on cable tie anchors, and dedicated stick-on wire holders, that'll make this easy.
Mysterious vanishing megabytes
I have a problem with some SDRAM. Recently, I sold through eBay two 128Mb sticks of PC133 RAM. Now the buyer has informed me that when he installed the RAM it read as if it was only 64Mb per stick. Naturally, he is convinced that I have sold him rebadged memory.
When I had the RAM it read correctly as 256Mb in total, in two different computers. I sold it because I've upgraded to DDR on my current motherboard. Is it possible for RAM to read differently in different computers? And if so, why is it reading exactly half of its capacity?
The sticks are different brands, same ratings and size, bought from different shops about 1.5 years apart. Can motherboard settings change the RAM capacity? Could the buyer have installed it in the wrong kind of slot? Could the RAM have been damaged in transit by an electrical or magnetic factor? Have you ever heard of this problem before?
Daniel
Answer:
I'm suspecting your buyer has a nasty old motherboard that's only seeing
one side of each module. A BIOS upgrade may help him; otherwise, he'll need
to buy single-banked (often called "single sided") RAM instead of the double-banked memory which I presume you sold him.
If you specified the RAM as double-banked in the ad and he bought it anyway, then tough luck for him. You probably didn't, though; this isn't an issue that everyday consumers usually have to deal with, and most people don't know it exists.
If you do an appropriate eBay search, though, you'll find that a fair few dealers specify.
If you didn't say it was single-banked, and he didn't know he needed single-banked, you might as well toss a coin over who gets to carry the can for this one.
The physical arrangement of chips may or may not indicated the bank arrangement of the memory. Single-banked RAM often has chips on only one physical side of the module, but not always.
Back when SIMMs were new (before our current DIMMs), modules that had chips on only one side were always single-banked RAM; SIMMs with chips on both sides were double-banked. They were two quite electrically separate modules that happened to be built on one piece of fibreglass. Double-sided single-banked SIMMs and single-sided double-banked SIMMs both existed later, though, and that situation's continued to our modern DIMMs.
Help for the aged
I have just received an old Toshiba T1200XE laptop, and it refuses to display anything. I know (or at least am fairly convinced) that it is booting up (I can hear the HDD).
You seem to be able to find information on pretty much anything, so I was wondering if you could point me in the right direction to getting it fixed.
Justin
Answer:
If you're going to pay someone else to fix a 286 laptop, then you're going
to pay a lot more than it's worth. Better to buy a new one on eBay and keep
the old one for parts.
If you're going to try to fix it yourself, then there are a number of things that could be the problem. It could just be set to output video to its VGA connector (I'm assuming it's got one...) rather than to its LCD screen, for instance. Or it could have a dead backlight - if you shine a bright light on the screen, you should be able to tell whether there's something being displayed but no light to see it by. Or it could have a broken connection to the screen, or a fault in the panel itself, or something wrong with the video hardware... you name it.
This plethora of possible faults is part of the reason why paying someone to fix it will cost you more than it's worth!
UPS repurposing
My boss just trashed a UPS because the battery needed replacing (so he upgraded) and rather than heaving it into the dumpster, I rescued it. Since I've been looking into getting an inverter for my truck, I thought maybe I might be in luck.
Can I just hook up a connection to my truck's battery and be merrily on my way? The UPS is rated for 480 VA (120V, 4 amps) and 285 watts. I'd want to plug in small things like a Discman or laptop or whatever.
Alan
Answer:
Assuming the UPS battery voltage is the same as your vehicle battery, yes,
provided the engine isn't running. It'll probably be OK even if the engine
is running, though.
The voltage issue is important. A lot of quite small UPSes are 24-volt units - they use a pair of the ubiquitous 12V 7-amp-hour sealed-lead-acid "gel cell" bricks in series. They won't work from 12 volts. Connecting a 12 volt inverter to 24 volts is, as you might imagine, an even worse idea.
The engine-running thing won't be a problem, if the UPS's inverter doesn't care about slightly elevated input voltage. It probably won't, because any decent lead-acid battery charger has to push a "12 volt" battery to more than 13 volts, in order to fully charge it. So the inverter really should be fine with at least 13.5V, and the 13.8V that a "12 volt" vehicle's alternator delivers is only trivially higher than that. Still, something might overheat, especially if you're using the inverter a lot or loading it heavily (which you don't seem to be planning to do).
Many cheaper UPSes do not expect to have to run their inverters for more than ten minutes at a time, if that, and vehicle electrical systems can surge and spike when you turn things on and off.
It's still worth a try, though. Exactly what you plan to attempt has been done numerous times, usually successfully, by nerds on the move.
Big LEDs
I see there are now 10mm white LEDs with an output of a modest 6000 MCD (4V 25mA, very few other details). They are pricey, though, at $US4.95. That same outfit has a set of three 10mm LEDs for a nicer $US8.95. Ever heard of these? Any thoughts about the merits of stuffing say, three 5mm together versus one 10mm, and on the differences of the effect that the one giant glob of 10mm epoxy versus three with the dead spot in the middle?
Now I can't be sure from the next picture, but an even better 10mm white LED appears to be only $US1.95 from B.G. Micro. Spec'd at 9000 MCD (3.5V, 20mA).
I do like those specs and price. But this seems strange, since they still sell a 5mm white (9300 MCD, 3.6v, 20mA) for $2.49.
I guess what I am really asking is the relative merits of all that extra lens on light projection, and presumably better heat dissipation in a 10mm package. What is also interesting is the 9000 to 9300MCD derived from only 20mA. Does that seem a bit optimistic, or are designs getting more efficient?
I haven't done this kind of math in a while, but does the light output in these jumps from 5mm 9000MCD@20mA to Luxeon 60-100x MCD multi-watt LEDs graph out in a linear or asymptote-ish fashion? Are we pumping more juice to get a tiny bit more candlepower thus bumping into the law of diminishing returns? How far can they go?
2) Speaking of B.G. Micro, there is something completely different over there. A so-called LED "Flasher" for $US3.49. Here is their hype:
"This RGB flashing LED is a winner. Apply 4.5Vdc, 90mA and let the fun begin. The LED flashes red, then green, then blue. If you leave it connected, the LED goes through a multitude of flashing, fading, dual colors, etc. Display your own personal "light show". The flashing rate, at start up, is 1.4 times per second(1.4Hz). Let your mind run wild and figure out new places to mount your new prize. All of this and it is in a T1-3/4(5mm) case."
Gotta admit that I have never seen one of these psycho "flashers", at least not in a normal package. One thing for sure, I have a real urge to cut one open! That is, unless you already have ;-).
Finally, on the lighter side, Aren't you really Yahoo Serious? (no offense! I like that movie). Ever since you put that photo up of you holding those hemostats I see you as Young Einstein :-).
Nomad
Answer:
10mm white LEDs have existed for some time; electronically they're exactly the same as
5mm LEDs, but just have bigger lenses. This lets them focus more tightly, though
they don't necessarily - like 5mm LEDs, they're available with various beam
angles. The shape of the epoxy lens package stays pretty much the same for
different beam angles, but the position of the die inside the lens changes.
LED millicandela ratings change with the focus - the tighter the beam, the higher the "mcd" figure, with no difference in the actual amount of light being thrown at all. Different LEDs may well have different real light power, but you can't tell from the mcd figure.
(I talk about this in the "Decoding light statistics" part of my old LED flashlight review here.)
Luxeon LEDs are actually more efficient than smaller ones (though, as with all LEDs, their efficiency starts out miserable when they're not getting enough volts, then rises to a peak, then trickles down again on the overdrive side of the curve).
On the subject of LED comparisons, you might find this PDF file interesting.
The limiting factors for LEDs are efficiency and cooling, but all sorts of interesting things are being done in the young nanotechnology industry to improve both factors. So it's quite possible that white LEDs (probably not using today's blue-LED-plus-phosphor-blob design; some quantum-dot-based design seems favourite at the moment) will be as efficient as fluorescent lights, or even better, in not very many years.
Don't ask me where the limit is, though; it's like asking someone in 1912 how fast aeroplanes will one day be able to fly. All I know is that there's very good reason to consider it impossible for even a monochromatic light (as opposed to a multi-wavelength "white" one) to ever achieve more than 603 lumens per watt.
On the subject of the flashing RGB LEDs, I haven't cut 'em, but I've seen 'em. They're used in lights like the rainbow "Psycho-Bright" I reviewed here. I also found that the bare LEDs are very easy to work with.
And on the subject of being Yahoo Serious, no, I'm not.
I also see that you, like many others, liked his second film so much that you don't even know it exists.
And oh, dear God, there was a third, too.
Could be worse, though.
All aboard the Free Gear Express!
I am starting a site like yours and was wondering if you have to pay for the products you review.
Since I am on a low budget, I was wondering if companies will even hand out products to be reviewed in the first place to a small hit web site like mine.
It seems they contact you, but when you first started out, how did you go about contacting companies to review their product?
Curtis
Answer:
Do I pay for review product? Hell, no!
But I don't sell it after reviewing it, either, so it works out pretty even.
You're unlikely to have much luck getting anything for review, from anyone, if you haven't already written at least a few reviews. Start out by writing about something you know about. A new game that you've played far too much for two weeks. Some item of hardware that broke, and you fixed. How to configure a poorly documented free firewall program. That sort of thing.
Once you've got a piece or three on the Web, you can start pestering people for review gear. Cheap gear - CPU coolers, mouses, stuff like that. Thermaltake, for instance, tend to send their products to people who haven't even asked for them!
Write good reviews of that stuff, and your humble requests to second-tier motherboard companies for review product may be answered favourably. And on it goes from there.
You can also try getting review gear from local retailers and distributors. These people aren't likely to give you anything, but they may well be happy to lend it to you, in return for big "you can buy this from..." plugs in the review. If that turns out to be a big winner for them, you can start charging them a decent amount per clickthrough, provided you don't have lame "Click here to support this site!" stuff around the links that encourage random non-buyers from Bogota to click through. Retailers want buyers, not just zillions of pageloads. Look at my Aus PC Market links, for which you'd better believe I'm paid (no, not for that one just then), to see what I'm talking about. And hey presto, you'll be making money with your Web site.
Write crap reviews and you'll get nowhere, of course. You probably don't need me to tell you that, but heaven knows there are lots of hardware sites out there that haven't quite realised it yet.
Geography news
The Earth is flat and has five corners!
I think it's a joke...
Nathan "Soyfu"
Answer:
That Flat Earth Society is indeed a
joke,
but the International Flat Earth Society is
100% serious. Not all
of the IFES's members are entirely sincere, though, just as not
everybody with a diploma from the Universal Life Church is actually in the business of marrying people
and/or distributing religion.
