technology and zen of life

“A heisenbug (named after the Heisenberg Uncertainty Principle) is a computer bug that disappears or alters its characteristics when an attempt is made to study it.”

Best free productivity Android Apps for S3

Now that you just got yourself one of the best smartphones around the Samsung Galaxy SIII it is time to start installing apps on it. Galaxy S III already comes pre-installed with apps like. Google Search, Maps, Navigator, Gmail, YouTube, Calendar, Google Talk, Picasa integration, Swype, Dropbox etc. Here I have jotted down some more essential free apps for Galaxy SIII to get the most out of your phone. Though this list is focused on S3 most of these apps are good for any android device.

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Reverse-engineering the cascode

(from – http://analogcircuits.posterous.com/reverse-engineering-the-cascode)

Cascode (shown in Fig. 1) is well known and widely used circuit for creating large-impedances in integrated circuits. Cascode circuits also provide another advantage i.e. isolation between input and output ports and thereby reducing the Miller-effect and as a result cascodes have a good frequency performance. And when impedances achieved from cascode circuits are not good enough, we go on to use active-cascodes or regulated-cascodes. Even though cascodes are affected by the limitations of headroom (voltage swing), there are work-arounds for this problem that have been figured out by circuit designers (the smart engineers again). The question that I want to discuss here is – how did someone (must be a genius) think of this circuit which provides an elegant area-efficient solution for achieving large impedances consequently large voltage gains?

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Why do we perform small signal analysis?

Why do we perform small signal analysis, when we are analyzing or designing analog circuits? This is a fundamental question that I think, is not discussed rigorously enough in the classes or text books on analog circuit design. I will attempt to qualitatively address this question here in this blogpost.

Untitled Why do we perform small signal analysis?

Fig. 1 a) Small-signal MOSFET model and b) small-signal bipolar model

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Testing rechargable batteries

Author: Bob Westerbrink

Rechargeable batteries aged 6 years or older are, in general, garbage (this also is true for most car batteries). How good are your rechargeable batteries? You can test your batteries by measuring the time it takes until they are empty while they power a LED or something similar with a small resistance. It’s easiest to use a resistor.

You need a:

Bypassing the DELL unrecognized adapter issue

Dell is notoriously infamous for selling adapters that tend to go bad after few years of heavy usage. In the last 3 years of my laptop use, I’ve already had to change my adapter thrice due to an unrecognized adapter bios warning. You can read about why this issue occurs here .

I don’t really mind this message but dell has gone further to annoy their consumers by forcing a cpu throttle to the lowest scaling frequencies. Also, they will not allow you to charge your battery if this message pops up, for no reason but to force you into buying a new adapter. Since this is expensive business and all three of my dead and dying adapters work perfectly fine as far as the voltages required for operation are concerned, I was desperately searching for a software bypass to somehow allow frequency scaling on my CPU and work on reasonable speeds. However googling didn’t help much at which point I started reading up on BIOS and ACPI, the ones responsible for power management. Finally, I stumbled upon this beautiful solution to bypass this limit dell forces upon me.

On probing ACPI on the linux kernel I came across /proc/acpi/processor/CPUx/bios_limit which is the limit the bios is asking the kernel to respect. Hence, all one needs to bypass it is to ask the kernel to ignore bios_limit using a kernel parameter via grub namely processor.ignore_ppc=1. So just add this line to grub.conf [ or to GRUB_CMDLINE_LINUX in /etc/grub.d/grub if you're using grub2] and you’re set.

Alternately, you can use rmclock[gui] on windows to achieve the same. However don’t forget to set the processor type to mobile if you’re using a laptop to get the right voltage values for various p-states. I hope this helps folks who’ve been annoyed by the way dell handles its adapters like me.

Linux/Fedora 7 and ATI Graphics Card.. eh ?

Hello windows users!, and hello fellow Linux (in particular Fedora 7) users icon wink Linux/Fedora 7 and ATI Graphics Card.. eh ?

Yeah, I just installed Fedora 7 on my new Sony Vaio laptop, and it works great. I still have to figure out few new things, but I am happy as it’s working for almost everything I need(I just need a console, few manuals, a browser and Internet). Here are few tips for people who don’t find much help on ATI Graphics cards and Linux(in general).

  1. Install Linux in text mode, few Linux distro’s (like ubuntu) use graphical install, which won’t work for you. There are bootup commandline switches (generally accessible by hitting F1). Fedora 7 has command line installation option from the boot menu itself so it’s easy there. Note you might need ubuntu alternate disk to use the commandline install, I used alternate-install disk. Always try to get DVD versions of installations whenever possible.

  2. Fedora 7 DVD version has support for my Wireless Card (Intel(R) PRO/Wireless 3945ABG Network Adapter) out of box so it saved me hassle of getting on to a wired network for installing the ATI Graphics Drivers, which can be found at ATI website. Here is the kink in the story, I needed to download it from the website, and I don’t know how to use those text based browsers, so I needed to use laptop of my room-mate to get the link of drivers I needed.

  3. Used wget to download the drivers ( The link for Linux x86 32 bit computers is https://a248.e.akamai.net/f/674/9206/0/www2.ati.com/drivers/linux/ati-driver-installer-8.40.4-x86.x86_64.run ) Pasted the link so that you can (type it for wget), Alternately the link is here.

  4. To install the drivers you need to execute this command

./ati-driver-installer-8.40.4-x86.x86_64.run –buildpkg Fedora/F7

If you are using some other distro of Linux you will need to find the correct switch, execute this command and read the instructions that come on your screen.

./ati-driver-installer-8.40.4-x86.x86_64.run

a useful hint is you will need something like

./ati-driver-installer-8.40.4-x86.x86_64.run –buildpkg <switch>

where <switch> is the missing argument.

5. One you get the things set, under Fedora 7, you will get about 5-6 RPM files, you might choose what you don’t want to install, but for me as a new user, I just installed all! If you are interested in finding out which file does what, then you might want to go on some IRC Channel to ask. Nuf said, to install the rpm files use

rpm -ihv *.rpm

in the directory where the driver rpm’s are present.

6. If you get dependencies error use

yum install <missing dependency filename>

under Fedora 7, I believe “apt” can be used in similar way

7. Type gdm while you are logged as root, or use startx as normal user

8. All done? You need to follow this link to get a graphical display on bootup

http://www.linuxquestions.org/questions/showthread.php?t=7381

9. All right reboot!, use reboot command on the console.

10. Post as comment what you see when you reboot icon smile Linux/Fedora 7 and ATI Graphics Card.. eh ?

Note : This guide is written by a Linux newbie for Linux newbie, who has experience of working on Linux for few months, mostly for shell scripting and network programming, so he mostly worked on a terminal. Keep that in mind. This guide is written by sheer lack of Google results and support on forums for “Linux and Sony Vaio” or “Linux and ATI” when compared to “Linux and Nvidia” on any forum. Use it at your own risk. I am not responsible if anything goes wrong with your system/computer/laptop.

Things you can do to keep an old PC useful : Part 1 (Hardware Tweaks)

Hello,

This is the first one in the series of multiple how-to’s.

First of all expectations. What do you expect out of your old PC after you are done with the tweaks mentioned here? Clearly if you expect your Pentium II or Pentium III to run Doom3, then you should stop here. Although you might see some performance boost in your computer, it might be just enough to run a few applications together, along with a media player playing a movie.

You might say, “I can still watch a movie, while working on my text editor, and with browser open.” Well I say that If you can get some performance boost after reading through what’s the harm.

Here are few hardware tweaks you can try.

Keep the hardware clean : Anyone who knows even a little bit about hardware knows, if you really want to keep your PC running at peak, you must clean it regularly. This even goes for newer PC’s which tend to run at higher processor temperatures. You must clean cabinet regularly, while the processor fan/heat sink must be cleaned every once a while. You might see 5 degree Celsius drop (at times) in the idle temperatures of your processor.

Simplest way to clean the cabinet is by using your vacuum cleaner to blow all the dust away. While cleaning the processor sink and fan might need unhooking them from the motherboard, which can be quite a work, but once you clean it you can see the change in performances/temperatures.

Visual Guide : http://www.crazypc.com/articles/hsfinstall.htm (the guide is a bit old, and the process of unhooking the fan/sink might vary for different motherboards/processors)

Actually for me it includes cleaning the motherboard with a brush/blower, then unhooking the heat sink, removing the old thermal paste, washing the sink with water, cleaning the area near the processor. Putting some thermal paste and putting the sink back in place after it’s dry. Finally hooking the fan again. This can be quite dangerous to do as per the motherboard/processor manufacturers but works for me. I don’t use any anti-static materials etc. You must clearly think of what are you handling before going following this way.

Adding/Increasing memory : Simplest way to get a performance boost in old systems is increasing RAM. If you don’t want to upgrade your whole PC, hook up some more RAM and see the difference. But getting hold of SD RAM(PC 100/133) can be quite difficult. You might wanna check with local vendor to buy a second-hand RAM. But first check how much RAM your motherboard supports, which mostly is 512 MB or lesser for old motherboards.

Before closing if you do read this and try it out, please do comment about your experiences with all the cleaning and the performance boost.

Disclaimer : Cleaning the motherboard could be dangerous if not done with caution, read the motherboard handling guide given by your motherboard manufacturer, same goes for the processor. I am not responsible if you screw up your PC in the above process. REMEMBER “I told you how to screw up your PC, but you are the one screwing it up.”

Keeping an Old PC still running

Hi people.. this is just a formal note that my next few posts will be about how you can keep an old PC still usable. It will contain multiple how-to’s, and everything I have learnt by observing people around me, while they struggled with their 3.2GHz Intel Proc’s and 1GB /512MB RAM to get Windows Media Player to play an video file properly. Keep reading and RoK on !

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The views expressed on this blog are personal. We do not claim to be a representative voice of the views of any organisation whatsoever. We are not responsible for the content present on the blogs to which we have linked.Views expressed are solely that of the author and does not reflect a collective opinion of contributors.