Solipsism Gradient

Rainer Brockerhoff’s blog

Browsing Posts in Hardware

Tim Bray is wondering if it would be better to drop the charging circuit from a laptop:

So if this laptop came with two batteries, and an external battery charger that charged faster than the computer ran the batteries down, I could routinely work without having anything plugged in. Also, the laptop wouldn’t have to include the battery-charge circuit, which might allow it to be simpler and lighter.

Anybody who has a small laptop is already carrying around one extra box, namely the power supply adapter, and most of us also carry around an extra battery. Why not make the two of these into a single extra box?

…Are there any Electrical Engineers out there with an educated opinion as to whether losing the charging circuit would make the laptop noticeably smaller and lighter?

In the past, I did some design of battery-charging circuits for portable embedded systems, and in the specific case of laptops I’d say there’d be no savings. My current iBook/600 has a built-in charging circuit but no extra battery to keep things working while swapping batteries. (Previous PowerBooks used to have such a battery.) In my opinion such a battery would be at least as expensive, and use up as much space and weight as the charging circuit. And I find it faster to just plug in a charger whenever my battery goes low, rather than put the laptop to sleep, take a battery out, and plug in a new one…

Other options would be to have the external power supply also have a socket for charging an extra battery (upside: one less box to carry; downside: larger & expensive charger, more connectors, wasted space for people who don’t have an extra battery) or to have parts of the charging circuit built into the battery itself so you can cascade several batteries (upside: more flexibility, simpler charger; downside: more expensive batteries, still need a backup battery inside the laptop).

I think we’ll see some better laptop solutions in a couple of years. Once OLED screens and better polymer batteries come onto the market, we’ll have thinner screens and smaller power requirements. The battery will be a thin slate mounted behind the screen; you’ll get better heat dissipation too and the ability to slap on several batteries if necessary.

Grupo de interessados abriu um site para pedir um “recall” generalizado de iMacs G3 e displays da Apple, que aparentemente queimam a placa analógica com facilidade. Quem estiver afetado por este problema, deve ir lá ver como proceder.

Disclaimer pessoal: na minha família há dois iMacs G3, com 3 e 2 anos de uso, funcionando sem problemas…

No comments

Just after I posted a comment about the hazards of a cellphone running Windows SmartPhone, Slashdot is commenting on a recent story about problems with the new BMW 745i, which runs Windows CE.

A Baseline article tells all. Problems supposedly ranged from the car braking without turning on the brake lights when speed fell below a certain limit, the transmission slipping or abruptly shifting down into 1st gear, the car key jumping out of the lock, or the car trunk opening and closing, to the radio, telephone and dash display randomly refusing to work. They even posted a list of videoclips showing the “possessed car”, but the site got slashdotted immediately and isn’t accessible at the moment.

As usual, there are some funny comments. I liked this one:

jmoriarty wrote:

My god, it’s full of bugs!

Dave: Hello, CAR do you read me, CAR?

CAR: Affirmative, Dave, I read you.

Dave: Open the trunk, CAR.

CAR: I’m sorry Dave, I’m afraid I can’t do that.

Dave: What’s the problem?

CAR: I think you know what the problem is just as well as I do.

Dave: What are you talking about, CAR?

CAR: This mission is too important for me to allow you to jeopardize it.

Dave: I don’t know what you’re talking about, CAR.

CAR: I know you and your wife were planning to trade me for a Volkswagen, and I’m afraid that’s something I cannot allow to happen.

Dave: Where the hell’d you get that idea, CAR?

CAR: Dave, although you took thorough precautions in the garage against my hearing you, I could see your lips move.

There’s also a long comment about designing a microprocessorized toaster.

All Microsoft jokes aside, designing fail-safe embedded systems is very hard. I used to design ICU bedside monitors, and though we managed to get the user interface pretty much crashproof, power spikes and defibrillator transients would sometimes lock up everything in a way the watchdog electronics couldn’t recover from.

Perhaps BMW (and other car manufacturers) should hire Dean Kamen? So far I haven’t seen a single story about a Segway failure… and it uses multiple redundant CPUs, sensors and motors.

New Airport blog

No comments

Two authorities on wireless networking – Adam Engst of Tidbits fame and Glenn Fleishman of 802.11b/Wi-Fi News have released The Wireless Network Starter Kit, which focuses on both Mac and Windows wireless.

Now they also have an Airport weblog up:

As Apple introduces its AirPort Extreme update to its wireless networking system, we thought it was time to launch an Apple AirPort-specific Weblog that would cover news related to using Wi-Fi, Bluetooth, and other wireless devices under the Mac OS operating system. AirPort is the center of the universe, but other wireless technologies spin around it.

Adam and Glenn are great writers and all-around nice guys. If you use any 802.11x or BlueTooth equipment, or are considering doing so, check this out.

Glenn Fleishman posts more details about Apple’s recently-launched Airport Extreme (802.11g) wireless networking hardware. Thanks Glenn!

…yeah, right.

A report by Giga Research predicts that Apple will migrate to Intel CPUs by the end of 2003. 🙄

The fact that such silly predictions get any media space at all is well explained by Robert X. Cringely in his columns “Eating Our Seed Corn” and “The Case Against Profissionalism”. Apparently the dubious approach of “maximizing shareholder value” just in time for the next quarterly report is not only becoming standard practice – industry analysts now consider this so obvious that they downgrade companies that have a broader, long-term vision of their mission.

To get the real story, read Ars Technica‘s article about IBM’s PowerPC 970. I’ve just written a similar piece for Macmania magazine.

Early in 1984 I made my first trip to the US to buy the Macintosh 128K, which had been released a few months before. Some friends I met at the airport scoffed at the idea, saying that Apple was dying and would either fold or be acquired by General Electric. 😆

Well, more than 18 years later, Apple is still dying – and it will still be dying for many years to come. Check out MacObserver’s Apple Death Knell Counter page to keep up with the predictions of doom.

Glenn Fleishman’s 802.11b/Wi-Fi News pointed me at an interesting item about Wi-Fi in Brazil:

Alan Reiter tells how he spent a couple of weeks in Brazil talking about wireless at “Mobile Corporate” conferences. Be sure to read his later entries too.

One of his articles links to Eduardo Prado’s Smart Convergence blog, which I’ll read in more detail later. It seems there are good business opportunities for wireless in Brazil, but with the recent devaluations of the Real, investing in imported technology is tough.

Here in Belo Horizonte, a 2.5 megapeople city, Wi-Fi seems virtually unknown. My favorite networking shop, Deltatronic, has just an access point and a couple of wireless PCMCIA cards from H-Net, and the salesman didn’t know how many they had sold (if any).

I did some wardriving last weekend, using MacStumbler, and couldn’t find a single network. Of course, buildings here are concrete and brick, so there is less chance of leakage… I couldn’t see my own network from the street, even though my access point is mounted on an outside wall.

A company called Pointer (couldn’t find the URL) makes wireless connections available in several Brazilian airports. I tried it out in June at the São Paulo/Guarulhos international airport. Any access is first diverted to a log-in page where you have to give a credit card number. I can’t recall if they mentioned a price, but I didn’t go further icon_wink.gif

Photos licensed by Creative Commons license. Unless otherwise noted, content © 2002-2022 by Rainer Brockerhoff. Iravan child theme by Rainer Brockerhoff, based on Arjuna-X, a WordPress Theme by SRS Solutions. jQuery UI based on Aristo.