May 8, 2013

Apr - 25 2013 | By

Additional notes

Notifications of new show notes and edits are tweeted at:
– They're tagged with #Zentech.
– When what's said is unclear to me (or I'm unfamiliar with a topic) I tend to quote (" ") verbatim.
– Editor's comments are delimited by < >

The guys seemed to think there is not a 5th Wed this month and said so at the end of the show. Well, according to my calendar, the 29th is the 5th Wednesday.


Paul was in the studio by himself. Glenn joined in by phone.

The show opened with music by Weird Al. <See the above link>

Glenn got a battery backup case for his iPhone. It cost him less than $7 including shipping, from Ebay. The good deal was due to its color — yellow. The case contains a chargeable battery, which then charges the iPhone battery, according to the way Glenn explained it.

Paul then told us about the battery-saving strategies that cell phones use when communicating with the towers. Where the cell signal is weak the phone has to put out more power to stay connected, thus draining the battery faster. Inversely, a stronger signal from the tower means the phone uses less power.

Glenn said, in his experience, he's found that to be true and gave tips to conserve the battery.
– Turn off Bluetooth.
– Turn wi-fi off.
– Doing a lot of uploading, like videos, will flatten the battery sooner.
<Related: Making your lithium battery last longer:>

Paul said that a large part of the operation system in a mobile device is devoted to conserve power.
– It doesn't continuously listen for a signal.
– It doesn't constantly send a signal at full power to reach a cell tower. – – It uses a complex algorithm, pinging the towers with short signal bursts. And then it uses "reciprocal backoff": it extends the time between pings until they come about a minute apart.

Paul said if you place your cell phone near an amplifier or even a PC speaker, you can tell from the noise you hear if a call or a text is about to come in.

Paul thought Ebay does a great service by recycling (reusing) used equipment and parts. For instance, parts (like keytops from keyboards) are sometimes stripped out of obsolete equipment and resold instead of ending up in the dump. He also mentioned Freecycle — a website to find recycled parts,

The guys then talked about the Maker Fair. Glenn said the idea stared with a dad helping his daughter with projects, and that led to the magazine called Make and, eventually, to get-togethers (fairs). He recounted how he and Paul got drawn into a local group called The Courious Forge. Now there are fairs in many parts of the country, like the well known The Crucible in Oakland. The next big regional fair will be in San Mateo on the weekend of May 18th & 19th. Links to Maker Faire & The Curious Forge are above.

When men talk while doing other things (multi-tasking), their voices tend to become monotone. Paul said that's not noticeable when it comes to women. Supposedly, men have a serial brain, women a parallel brain.

Up until a few years ago, CPU's did things one at a time. They would rapidly switch between tasks to do multiple things: displaying your email, running Microsoft Word, checking for keyboard activity, etc. These days, Paul said, he would not buy a computer that didn't have at least 2 brains that are multi-threaded: where the operating system assigns different tasks to each of the brains. Some of the latest processors are "duo core duo chip" (essentially 4 chips). Not all applications can make use of this feature. The Adobe Creative Suite version 3 (approx.) or greater does make use of this facility.

Ely called about creating a website and wanted recommendations for a web host (the place where webpages reside).
– A good web host should be cheap, no reason to pay a lot of money, maybe $50 or $60 per year. The guys won't endorse a particular host except for Also check out
– If you see a website you like and want to know who the host is, you can go to Submit the web address of the website and it will tell you the software it uses as well as the host.
– Many hosting sites offer a free trial period.

Ely is learning to use HTML and Paul didn't want to discourage Ely, but there are newer & better tools for creating webpages. These tools may create HTML as you use them, but you'll not have to deal with HTML directly.
– Try You can create a webpage there for free.

Glenn asked about HTML5. Paul said that's the latest iteration of HTML. It has the ability to render video "and stuff".

Ely creates games that use HTML5. Paul said in that case you may indeed have to deal with the HTML code itself. It may be possible to insert HTML directly into WordPress while creating a webpage, but he wasn't sure. He also suggest that Ely explore AJAX: a mix of HTML and Javascript, which is sometimes used for gaming.

Thinking Paul said Java, Glenn cautioned us that it's had some vulnerability lately. Paul said Javascript is different from Java and that it's a good idea to uninstall the Java Virtual Machine, but it has nothing to do with Javascript.
<Talked about in the 1-23-13 show. See the notes for related articles,>

Paul then talked about a version of Linux called Ubuntu. This operating system will sometimes run on older equipment that would otherwise be trashed, giving it a second life. Ubuntu is usually run from a bootable CD, so the old computer will have to have a working CD drive <and be able to boot from it>.

The current version of Ubuntu is 13 but it seems to be somewhat flawed so Paul said he's sticking to version 12.04, which has long-term support. It's "generationally frozen", meaning it won't change much over 4 or 5 years.

The Macbook Air doesn't have a CD drive, making it problematic to install software from CDs. The latest Macbook Air doesn't even have an Ethernet connection, only wi-fi. And wi-fi is not particularly fast and it's prone to interruptions that can interfere with an installation.
– You can stick the CD into a PC and share it on a network <where the Mac can see it>. But if it's a Mac-formatted CD, you "can't sensibly share it from a PC".
– Create an ISO image. <See the above link> Make the name of the file end in .iso and send the file to the Mac. The Mac can understand that file type and can mount it on the desktop. It's as if you had shoved a CD into a drive. The Mac can then use the file as if it were the original CD.
– This trick won't work with movies because of the copy protection scheme they use.
– The CD must not have any defects. Paul said that it should be perfectly ok to wash the CD using detergent and then carefully dry it.

Steve called with a question about his Netgear wireless router. He said it would work for a while and then stop receiving from the internet. It's about 6 years old and is connected to a cable modem.
– They are cheap enough, just replace it…about $20. But you should determine the router is the actual problem, not something else.
– Verify that your cable service is not the problem. Steve did, by plugging the cable modem directly into the computer: problem went away.
– Steve said the problem goes away when the router is connected to the computer by cable. It only happens when he uses the wireless portion of the router.
– As more of your neighbors get wireless, interference can become a problem. Check your list of detected wireless networks. If there are a lot of them, interference may indeed be the cause.
– If you suspect interference, run the software called Netstumbler to give you info about what channels the neighboring transmitters are using. You may be using the same channel as one of your neighbors.
– Cordless phones use similar frequencies. Keep them far away. In fact, unplug them while you're diagnosing the problem.
– Older phones & routers used 2.4gHz and tended to interfere more than modern equipment. Both types of devices tend to now use 5.8gHz but are designed better to avoid interference.

There is a method that Paul is not recommending and that he's never tried, to avoid interference. When you rest the unit <router, I assume> pick the channel group that's used in Europe. That can make it easier to find a channel to use that's different from your neighbors. However the authorities may detect your use of those channels and cause you grief. So remember, you didn't hear it on Zentech.

Scott called. He got a CD from KVMR when he became a member but couldn't get it to play on his Macbook Pro. When he puts it in the drive he'd get the message "you inserted a blank CD". The CD works fine in his (physical) CD player.
– The music may have been burned as data files <.mp3> rather than audio format <Red Book Audio>
– Bring the disk back to KVMR for an exchange. But Scott said it's not that important, he was just curious about the cause of the problem.
– CD drives in computer suffer badly even if they're not used much, even in as little as 3 years.
– You can try a CD cleaning disk.
– As a last resort, try blowing the drive out with air. But that may dislodge dust and put it someplace else, causing more problems.

You too can become a KVMR member.

Last updated 11:11 PM 5/8/2013

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