Just a short article this time.
More and more linux distros are getting into what is known as a network install.using ipxe. The latest one I have seen is Arch linux. Never used arch linux, but people whohave used the network install say it makes for a more efficient system when setup is finnished. More details at:
Interesting idea to modify for a portable laptop stand . This is just a crude prototype.
Found a nice little hack with youtube-dl. Youtube-dl allows you to manually download youtube videos. Downloaded several videos but they sere all saved as mp4. Not only does that waste space, but my old machine can not really handle that format. in looking at the documentation, there is a command line switch that will on the fly convert formats according to the following table:
-f FMT, –format=FMT
Specify the video format (quality) in which to download the video.
For youtube.com, in particular, the meaning of the format codes is
WebM video at 480p: 43
WebM video at 720p: 45
H264 video in MP4 container at 480p: 18
H264 video in MP4 container at 720p: 22
H264 video in MP4 container at 1080p: 37
H264 video in FLV container at 360p: 34
H264 video in FLV container at 480p: 35
H263 video at 240p: 5
3GP video: 17
Note that not all videos are available in all formats and that
other sites supported by youtube-dl may have different conventions
for their video formats.
So for me I used;
$ youtube-dl https://www.youtube.com/watch?v=xxxxxxxxxxxx -f 34
Now files are saved as flv with a space saving up to 75 %.. Where I had problems with the mp4 format, the flv formatted files play perfectly.
Most portables require a special cable to interface with a usb to thernet adapter. For the Nexus 7, you will need an OTG (On the Go) cable. they are fairly inexpensive. You can add a powered hub and attach a keyboard and a number of other items.
Thanx to everyone for help getting us over 500,000 views at http://www.instructables.com
Old memory from an upgraded laptop to upgrade diskless thin client to work with the our latest ltsp server.
Went to Frys and it seems as if they had dumped the Arduino and all all the micro-controllers. I inquired about it and was directed to a manager. I had finished my business there so I said I would ask later. The later in the day I stopped by Radio Shack. They were kind of dumping the Arduino. Got an ethernet adapter for a good price. Now the carry the Seeed products. It is an arduino clone. Their add on boards were half the price of the Arduino stuff. Check it out.
Love virtual machines as you have have several os’es running at the same time. Very memory intensive though. On a debian base system. the virtual machines ard arch linux, Centos, and a instance of debian with the KDE Desktop. Also great for testing software you are not sure about.
Followup to the cable making. You will also probably have to make a female end at one time or another. They are easier to prepare than the regular ends. The will be inserted from inside the wall in a face plate
The connector is color coded with the standard wo-o-wg-bl-wbl-g-wbr-br. Not always in that order. Note the B and the A markings. Since the B type cable is used most often, the color chart is on the top.A so all you have to is is slide the proper color wire in the correct slot and then punch it down.
Example of a punch down tool being used. notice the extra lenth of wire.Pretty simple and easy. You will end up cutting off the extra wire.
Once you have punched down all eight wires, you will cover the unit with the provided caps.
We just use cheap punch down tool that syou can get probably 5-10 for 3 bucks. Good punch down tools for for thirty dollars or more depending on where you get the tool.
A Ups short for interuptable power supply is to condition electricity for the equipment connected to the unit. Usually not all lines are used for that. Some of the power receptacles (where you plug in things) can be used for surge protection only. Usually the conditioned power receptacles will say they are for using battery backup and surge protection.
Since I mentioned the unit is for line conditioning, the ups will smooth out or clean the power coming in the the devices the ups protects. It also should protect against extreme situations such power surges and brownouts.
Most people know about power surges, such a protection against such dangers as lightning strikes. Generally that is true if the lightning strike is not a direct hit to your power lines. Some electrcity companies will install special surge protection on a home or building making it not usually necessary to have to use surge protectors in the building.
What a lot of people do not know about is brownouts. Sometimes this is called the silent killer of equipment. Surge protection will not help you in protecting from the brownouts. Brownouts can be more problematic than blackouts to delicate electronic equipment in some cases. Brownouts are defined as extended periods of voltage drop or sag coming from the power grid. In brownout conditions, most devices will continue to run, but with unexpected errors and possible long term damage to components. Brownouts can occur at the utility level like blackouts, but in many cases they can also occur within your building’s electrical grid, when a large local load is applied.
In a brownout, power supplies need to draw more current to compensate for the lower supply voltage, which is very stressful for transistors, wires, diodes, etc. They also become less efficient, which makes them draw even more current, aggravating the problem.
The ups obviously has a big job to do. There are actually two basic types of ups’s. One unit uses line power till the power goes out and then the battery takes over. The switching from the line power to the battery can leave a short time when equipment connected to the unit has a mini blackout which can cause problems for really sensitive equipment. Plus the part of the system that does the switching will eventually wear out.
The second type of ups has power always coming from the battery via an inverter . The line power via a power regulator keeps the battery charged as needed. In this case, no real switching needs to be done. That is an over simplication, but the power will or should be rock solid. Generally these types of ups’ are more expensive.
Given you just a thimble full lof information. You need to check out any ups that you might want to use in detail. But at least you have a bit of information to start with.
Adapter cable for the APC rj45-rs232 cable
The jack in the UPS may be easily use a 8 pin RJ45 connector. It is easy to construct the cable by cutting off one end of a standard RJ45-8 ethernet cable and wiring the other end (four wires) into a standard DB9F female serial port connector.
|PC Signal||PC pin||UPS Pin||UPS signal|
Oldie but goodie repeat. Under five dollar emergency telepromter (excluding cost of camera and computer/ Dollar store mirrir and glass pane from a Dollar store document holder. Boxes wherever you can find them.
Recently a local television station waas conning people to give up their old computers for free. It really upset me. Unless the equipment is dead, most of the old equipment is still useful. Here is an example of an old pentium being useful with Ubuntu 10.04. I probably could of even used a newer version, but I have not updated the server yet.
Update: Even more insane as allegedly :german-ministry-of-education-throws-away-pcs-for-190000-due-to-infection. http://www.heise.de/newsticker/meldung/Schwerin-Virus-verseuchter-Rechner-Ab-auf-den-Muell-damit-1851718.html. They could of been saved with Linux.
Coming soon we discuss separately ldap and the Cobbler server.
Baked chicken, but with more Italian seasonings instead of barbecue sauce.