Dan's Data letters #106Publication date: 26 May 2004.
Last modified 03-Dec-2011.
How do you reckon the BitHead would stack up for gaming? With Creative advertising 24bit/192kHz sound, I'm worried that the USB end might not be too impressive.
The BitHead (and USB audio devices in general, like these headphones) is fine for games, basically, but it has no hardware positional or environmental audio features. It's just a stereo audio adapter, so you have to use whatever software positional audio features your game provides. For a lot of games these days, that means Miles Fast 2D Positional Audio, which is better than straight stereo but not as good as any of the hardware-accelerated 3D options.
Modern PCs can generally handle software processing of more elaborate 3D audio schemes, though, so a straight stereo adapter can be tolerable. And if you're not playing games that need 3D audio, of course, then it doesn't matter at all.
My Versa M400 laptop is stated as a "P4 Mobile", at 2.4GHz, although in most stat programs on my laptop, it just shows up as a P4. I have physically opened it up, and the processor itself doesn't exactly scream "M". I was amazed at the massive copper fin/heatpipe assembly used to cool it. On the CPU are the following numbers:
Intel (m) (c) '02
etc. I assume the (m) means mobile, but why doesn't the CPU show up as "P4M" or similar in stat programs?
Also, I have noticed the iPod has a HIDEOUS secret. 15Gb HDD, but notes are limited to 4kb!
I'm trying my best to find a program to get around this, it's terrifying after saving so many documents to the iPod in .txt format to find them... butchered.
SL723 is the magic ID string. It's a "mobile", all right (well, assuming it hasn't been relabeled, which isn't at all likely for a chip built into a laptop). But it's still got a sixty watt Thermal Design Power!
I don't know why the ID programs don't report it as being a mobile chip.
I don't think there's a way around your iPod problem, except for chopping bigger files up into 4k notes. Apparently this can be done in a fairly elegant way. Well, on a Mac, anyway.
(A reader's now pointed out iPodLibrary to me; it does the same thing in Windows. It's only for third generation iPods, though, so owners of old ones are presumably out of luck.)
A section in letters #105 discusses CFLs. I have done exactly what Douglas is thinking of in a couple of lamps and rooms at home. I thought I should point out that, whatever the lumens, watt equivalence, and ability to replace the sun type claims are made, these things are as dim as crap.
They don't burn out though.
If you are looking for a topic to have a rant about, might I suggest e-book readers? I, like many self respecting technophiles, have long been awaiting a new generation of e-book reader to replace my old Palm 5x (it is the only time I read the classics - freeware from Project Gutenberg).
Sony released their whiz-bang, next generation, light as a feather, unbelievably wonderfully crisp display, last-till-I-am-100-on-4-AA-batteries, e-book reader device - the Librie.
Looks great, but once again, a manufacturer has developed yet another proprietary format to ensure incompatibility with all forms of existing digital storage, and an absurd digital rights management system that makes the whole expensive product useless. This one is a particularly good example of the marketing genius behind this phenomenon, demonstrating the following key features:
1. an absurdly limited launch date library of 400 titles (the entire library should be able to fit on the device, but for feature #2);
2. magnificent bloating characteristics (a 140k freeware text file is apparently being sold through the Sony shop as a 7.4Mb download and a single comic book as 24Mb) thus ensuring that all recent advances in flash memory capacity are cancelled out, and the thing is not able to store more than a standard circa-2000 Palm;
3. incompatibility with text, doc, HTML and PDF, to ensure that none of the billions of pages of existing digital content is useable on the device;
4. absurd digital rights system, with products time limited for 60 days (rendering the ability to have hundreds of books on a device useless).
I am not sure I would be able to more effectively ensure that the product fails if I tried. Have you seen a better example? I looked carefully at the press release to see if it was part of a John Cleese instructional video (you know the ones that deliberately get it wrong to illustrate the correct way) but couldn't see any sign of it.
I know e-books keep failing, but the idea is surely sound for some forms of content (newspapers and periodicals, technical resources etc). Would it kill a company to release something like the Librie WITHOUT a plan to dominate-the-world-with-my-proprietary-format built in?
I think I would actually buy one if I could read text, doc, HTML or PDF format on it, particularly if the new display technology is as readable as the reviews suggest.
Regarding the brightness of CFLs - I just did some low-grade science on the subject.
I bought a Philips 18 watt Warm White (a.k.a. Rather Yellow, like unto the yellowish output of ordinary filament globes) CFL, meant to be a replacement for a hundred watt incandescent.
I then installed it in a lamp, and pointed it up into the corner of my carefully calibrated ISO Standard Bedroom, and measured the light that bounced down to a meter sitting on the bed near the lamp.
(I was counting on this indirect light to iron out any effects from the funny shape of the CFL's bent tube compared with the small filament of an incandescent globe.)
The CFL took a few minutes to come up to full brightness; when it did, it scored 67 lux. It lit the room perfectly acceptably.
Swapping in one of the cheapest hundred watt incandescents it's even been my pleasure to buy - a shrinkwrapped pack of ten of 'em cost me, I don't know, 43 cents and some pocket lint - gave a result of 70 lux. Brighter, but not noticeably.
Super-long-life hundred watt globes are likely to score worse than this (they trade brightness for durability), and I dare say there are more expensive bulbs out there that'd score a bit higher. But the equivalence claim seems fair enough in this case.
Of course, the fact that the one I tried was honestly specified doesn't, of course, mean that the ones you tried weren't a complete swindle. This idea is supported by the Philips lamp's packaging, which has a double-asterisk next to the "Light Output" diagram, which leads to a disclaimer on the back that says "Guide only. Note: light output not equivalent".
So if it scored 3 lux then I guess they're covered. But this one, at least, seems fine to me.
CFLs may get considerably dimmer as they age, mind you; towards the end of the monster lifespan that encouraged you to buy one, you may be getting a lot less light than the initial equivalence figure suggested.
If you are looking for a topic to have a rant about, might I suggest e-book readers?
Regarding e-books - I babbled about them a little in not so long ago, so I think I'm going to have to come up with my own idea for the next Atomic Ground Zero column I have to submit.
As you say, the Librie is unquestionably shaded by a Dilbertian Cloud Of Doom.
The general consensus these days seems to be that the best usability and value proposition in current e-doc readers is the cheapest 320 by 320 pixel (or better) Palm OS handheld you can find. The extra resolution makes a big difference compared with the old 160 by 160 screens, and a Palm OS device can of course display every document format worth displaying, one way or another. Colour's nice to have too, but you can do without it.
The screens are still weeny, of course, but most people can get some use out of the other Palm features, and a basic 320x320 Palm OS something-or-other is just so much better value than any of the current dedicated reader gadgets.
The generic name for what you're looking for is a CD-ROM (or, these days, DVD-ROM) jukebox.
You'll probably find them a bit difficult to locate these days, though, because big jukeboxes are no longer a very good solution to this problem.
The better solution today is to keep your hundreds of CD-ROMs and DVD-ROMs for backup purposes, sure, but copy them all to image files on a hard drive and use a "virtual drive" program to make each file look like a drive with a disc in it. Even if every disc is completely full (700Mb per CD, 4700Mb per single layer DVD), you can fit 340 CDs or 50 DVDs onto a "250Gb" (actually around 250 billion bytes, or 232 real gigabytes) commodity IDE hard drive, which'll cost you a whole lot less than an optical jukebox of similar capacity. Since many discs aren't completely full, you may find quite a lot more fit on the drive than you'd think.
This solution is far faster than a jukebox. No disc swap time, no lengthy optical drive seek time, and you can access multiple discs at once with little slow-down. Jukeboxes with only one drive mechanism can, obviously, only serve up one disc at a time.
Doing this in Linux is (fairly) easy and costs nothing, provided you have a tame Linux nerd to hand. Doing it in Windows will probably cost you money. I don't know how well the free FileDisk program deals with lots and lots of drives; it may be fine for a whole alphabet worth of 'em. Daemon Tools is also free, but only lets you set up four virtual drives (which is generally quite enough for desktop purposes, but not for a jukebox). SimDisc is apparently good, supports up to 63 virtual drives in NT-descended flavours of Windows, and costs $US39.95. The usually recommended Windows package for doing this and various other CD duplication tasks, though, is Alcohol 120%. It only supports up to 31 virtual drives, though, and costs more than SimDisc.
All of your image files can be packed up portably in an external hard drive, if you like, and even if you only access it via USB 1.1 you'll be OK, if you don't need much transfer rate. A recent PC with USB 2.0 or FireWire ports, though, can access an external drive via those interfaces almost as fast as it could if the drive were plugged in inside the case, and you can hook up plenty of drives that way for awesome amounts of storage. You can buy external USB/FireWire drives pre-assembled and carrying the brand of various storage companies, or you can knock up the same thing yourself (or have it assembled for you at your local computer store) for less. I checked out a good option in the second department the other day.
I'm going to need to buy an AC adapter to power some 12VDC case fans for a project I'm doing. At the moment, I seem to be able to run two 12V fans in parallel off a 9V/1A AC adapter, however my multimeter tells me that it's giving the fans 12v. The fans are rated at 100mA, so I figure the total current through the circuit is 200mA. Why am I getting 12V?
Also, assuming I can find an AC adapter that gives me the voltage I want, how do I pick a good one? Dick Smith Electronics sells a whole range of them, and some of them are MUCH heavier than others. Why the difference? Does heavier mean better?
Lastly, curiosity has gotten the better of me lately and I want to know what the internals of an AC adapter look like, however it seems like you need a funny screwdriver (flathead with a slot in the middle) to open one. Can I buy such a screwdriver at my local hardware store? I couldn't find them the last time I went.
You're getting 12V from your "9V" adapter because it's not regulated.
Unregulated adapters are a very basic power supply - mains AC goes to a transformer (which is what makes the plugpack heavy), the resulting lower voltage AC goes to a bridge rectifier to turn it into DC, and the DC gets smoothed by capacitors. The capacitors hold the unloaded output voltage up to the peak voltage of the AC sine waveform, which is (for reasons you'll understand if you did a full high school mathematics course, and paid attention) root-2 (1.414...) times the nominal voltage.
This means a "nine volt" unregulated adapter will, when it's unloaded, deliver root-2 times nine volts, which is about 12.7V. If you load the adapter lightly (as you will, if you connect two 100mA fans to an adapter with a one amp rating), it's quite plausible that it'll deliver 12V. Load it up with another eight fans in parallel and it should deliver only its rated 9V.
Regulated adapters are different. They contain extra circuitry to hold the output voltage to its rated value, no matter what load the adapter faces (within its limits).
I became acutely familiar with this when I made my own metal-cased, super-heavy, very butch looking linear power supply for a battery charger, many years ago. I screwed up, and fed the charger 1.414 times the maximum voltage it expected. It ticked like a clock for a while (impressive, for a device containing only solid state components), got very hot, then stopped working.
The report from the (unsuccessful) repair guy read "Murdered By Owner".
In AC adapters, heavier no longer means better. Today, good AC adapters are lightweight switchmode units, containing no big low frequency transformer - just a little high frequency one. Jaycar have an excellent range of the things, for good prices.
But wait - there's more! Click here to go to page 2 of this letters column!