Tablet Computers

Slowly all the vendors are making tablets. I did not seeLenovo making any tablets and was thinking. Then last saturday in the news, read that lenovo is also with a tablet. And that too running Android 3.1 Honeycomb. So what next?

I have a wishlist

a. Bluetooth keyboards can become cheaper (around 20$) they are now around 80-90$.

b. If we can have a RJ45 port so that can use high speed LAN’s where they are available.

c. If we can have a Video output port. Majority of times I need to show presentations. Imagine no need to carry a laptop any more.

d. Ability to sync with PC’s with just plug and play.

Wait and see. In another 6 months this might be history.

Magic Square.

A magic square is a box (with n rows and n columns), with numbers from 1 x (nxn) used.

N may be even or odd. There is no known algorithm to make any even numbered square, but there is an algorithm for making an odd numbered square. Let me show you how to make a 3x3 magic square. Later you can try to make 5x5 or 7x7 etc.

Start with top centre, and put 1 here. Let us call this as location(1,2) where 1 is row and 2 is column.

	1

From this location (1,2) we go top and left. Reduce row by 1 and col by 1. This gives us row=0, and col=1. There is no row=0, so we put row=3 (last row). We put in this location (3,1)=2

	1
2

Top left of location (3,1) will be location (2,0). There is no column 0 so we take column as 3 (last column). Hence in location (2,3)=3

	1
		3
2

Top left of this location (2,3) will be location (1,2). But at this place we already have number 1. In such a case we go back to the original location (2,3) and go one column down. This is location (3,3). Here we put 4.

	1
		3
2		4

Top left from location (3,3) is location (2,2)=5

Top left from location (2,2) is location (1,1)=6

6	1
	5	3
2		4

Top left from location (1,1) is location (0,0). There is no such location, so we change to location (3,3), the last row and last column. But there is already a number here, “4”. So we go back to the original location (1,1) and come 1 step down to location (2,1). Here we put 7.

6	1
7	5	3
2		4

Top left from location (2,1) is location (1,0), no col 0, so get location(1,3). Here we put 8.

Top left from location (1,3) is location (3,2)=9

6	1	8
7	5	3
2	9	4

Try adding rows (6+1+8) or (7+5+3) or (2+9+4)

Or columns (6+7+2) or (1+5+9) or (8+3+4) or

Diagonally (6+5+4) or (2+5+8). The sum is always 15.

So try for a 5x5 square and a 7x7 square and post it here.

Mind Mapping

Mind mapping has been a favourite topic for me. In my trainings I usually incorporate this. I also teach the participants the benefit of it. And how to apply in their day to day work. While going through technical manuals with hundreds of abbreviations, and countless features mind mapping comes as a great relief.

Mind map is not connecting electrical wires to the head. It is a diagram. You can read a good piece of information here.

Now one way to put it in practice is using paper and pen. But with software things can be more easy. There are paid version. But me being opensource supporter, have found a good free tool. It is called the Free Mind project. You can get the details here. So take some time, download and use the software. I am looking for some Android version as well. Free ofcourse.

Video Converters : Free Solution

Now a days recording can be done from typically any device that supports photography. I have put down some devices and the formats into which they store the video.

Device	File Format
Digital Cameras	MOV, AVI
iPhones	MOV
Mobile Phones	3gp, 3gpp

But the format that we need to play on PC’s or on VCD’s or DVD players is MPEG. So there is always a need to convert these files from one format to another.

You can get a lot of paid versions of these software. But why not get a free software that promises to do all this. This way we can keep our memories intact. We can copy the contents to a CD, USB and give it to our friends to play those who don’t want to use computers.

One good software I found was Pazera Converter. You can search on google for other Pazera converters from any to any format. Download and install it. (Small file of < 5MB). Run the program. Please see the screen shots

1	Drag and drop your files that need to be converted
2	Select the format you want (for eg PAL-DVD)
3	Select the destination folder where you want to put the files after converting
4	This will get highlighted when you copy the files. Click this to begin the convert process. You can alternatively press CTRL+E.
END	Once converted use your favourite player. My fav player is VLC Media Player another opensource gem.

Images for Internet.

Cameras have gone high resolution today. Not only that, even the cameras on the mobile phones have gone high resolution. It is common to see a 3 megapixel camera on mobile phones. So what? you may say.

This has a few impact.

a. The need to touch images so that they look more presentable.

b. Reduce the size so that it can be uploaded to facebook or any where on the net where we want to. Reducing the size saves bandwidth on the net, and for those on slower connection can see the images.

c. Adding a watermark to your images.

We discuss the point b in this post. How to reduce the image size. I have found two good software to do this.

1. If your OS is Windows 7 or Vista or XP then use the Prish Image Resizer. Download and install it. It has no interface. It will be added to your right click menu.

2. Click on a picture, right click and you see this menu as example above. Choose Resize to 800. It will create a folder called Resized in the same folder where the image is. And inside the folder you have the resized image. Use this image.

Example. On my mobile (LG a 3mp camera and, taking an image size (2048 x 1536 pixels) results in an image size of 740KB. Resizing to 800 brings down the size to 100KB.

My Nikon gives me an image of size 4.5MB. Resized to 800 brings down the size to 86KB.

When you load say 50 images of your recent picnic or birthday, it not only saves bandwidth for others, but since your pictures can download faster, your friends will see all the pictures. If it takes too long to download, they may see the first few and never see the remaining.

How fast is your internet connection?

When we subscribe for internet or buy a plan, there are speeds that we are told that we are going to get. It is a good idea to check this from time to time. One of the best ways I found this you can do it on the net by going to SpeedTest.

This is the result of test that I did on my connection. Impressive. Great work StartHub.

Possibilities are endless.

The number of equipment that need electricity around us are endless. Mobile phones, Computers, Radio, TV etc. There has been need of various ways by which we could generate electricity. Traditionally what comes to our mind is Coal, Nuclear, Hydro, Wind etc. But what about our day to day life. Are there places where we can generate electricity for basic things. In rural areas of India as well as other developing countries this is a real challenge.

Please see this site, It is a Japanese site, with option to see it in English as well.

7-zip

Most of the people when think of file compression, two software come to mind. WinZip and WinRAR. Both of these software are good, but are not free. So if we are running them on our machines we better check if we are running the legal version.

Compared to this there is 7-zip. 7-zip is opersource and is hence free. It can do everything what commercial software do. Additionally you can unzip ISO’s as well as MSI’s. So if there is a small tweak that you need to do, or if you wanted to find some command line parameters of your installation media, us it.

You can download it from here. Very small in size. Has both CLI and GUI. I have been using it ever since I found it.

PDF Splitter

Many a times we need to split PDF files. We don’t have adobe full version to work with.

There are two ways we can do this.

a. Install and PDF printer and then print page by page. This is tedious but still workable.

b. A better solution is to download PDFSam. Please goto this site.

The beauty of this solution is as follows

1. It is free and open source

2. It promises what it does with no hidden catches.

So next time you want to split (or merge PDF’s) do use this. You may want to get some pages from a manual and send to a customer. You may want to split a huge book into chapters so that they consume less RAM while opening or less space on mobile devices.

Installing Apache and Perl. The easy way.

Below are the steps to get Apache and Perl running in simple steps. I am running all commands with root access. (sudo bash). In real life it is recommended that use sudo. So preceede all commands with sudo.

1. install apache-2

apt-get install apache2

2. start the apache server

/etc/init.d/apache2 start

3. In case you make changes you can either restart or just reload the apache2 server

/etc/init.d/apache2 stop

/etc/init.d/apache2 restart

/etc/init.d/apache2 reload

4. To remove apache2. Do not remove the /etc/apache2 folder

apt-get remove apache2

5. In case you remove the /etc/apache2 folder, you may not be able to reinstall the apache server. In that case do the following.

apt-get remove --purge apache2

apt-get remove --purge apache2.2

apt-get remove --purge apache2.2-common

6. Perl is already installed by default. You can do the following to do a test.

perl -h

7. You will need libraries for perl to work with apache2.

apt-get install libapache2-mod-perl2

8. Important Locations

   a.  /var/www is the default folder for apache.

   b.  /etc/apache2/apache2.conf  is the configuration file.

   c.  /etc/apache2/ports.conf  is the file which talks which port apache2 listens. By default it is 80.

   d.  /etc/apache2/sites-available  is the folder where you put the sites available.

9. Open a browser and enter http://127.0.0.1/   and if you see It Works. Apache is installed successfully.

10. You need a FQDN (a domain name). Let us say for testing you are using the domain skranga.test.com Then do the following

    in the /etc/hosts file.

127.0.1.1 ubuntu

192.168.101.133  skranga.test.com   myserver

How does Apache know that you want to use your hostname as skranga.test.com (in the above example).

To do this. Open the /etc/apache2/apache2.conf and add the following line anywhere.

ServerName  "skranga.test.com"

11. Goto the /etc/apache2/sites-available  folder

    Open the file default

-------------------------------------------------------------------------

ScriptAlias /cgi-bin/ /var/www/cgi-bin/

<Directory "/var/www/cgi-bin">

AllowOverride None

Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch

AddHandler cgi-script cgi pl

Order allow,deny

Allow from all

</Directory>

------------------------------------------------------------------------

Note :  Edit the ScriptAlias so that you give the folder where you will have your scripts.

        In the above case it is /var/www/cgi-bin. You have to create the cgi-bin folder.

mkdir /var/www/cgi-bin

        Add the line, AddHandler  cgi-scripts  cgi pl

        (this tells apache to execute the files with extention cgi or pl)

         Also if you read the full file, you will see a line like this.

        DocumentRoot /var/www

       This means all your html files will be in this directory.

12. Now to test everything is running, do the following.

a. goto the /var/www folder. Edit the index.html file. You can use test code like this.

---------------------------------------------------------------------

<html>

<body>

<h1>Welcome to Apache2</h1>

<p>---------------------------------------------</p>

<p></p>

<br>

Click <a href="http://skranga.test.com/cgi-bin/test.pl">Here </a>

</body>

</html>   

----------------------------------------------------------------------

In the /var/www/cgi-bin folder, add the file test.pl, with the following contents

#!/usr/bin/perl

print "Content-type: text/plain\n\n";

print "testing...\n";

Save it. and give it execute permissions.

chmod a+x test.pl

13. Now open a browser and enter http://skranga.test.com/  and you should see the page ("Welcome to Apache2")

    And when you click on the link, it should execute your script.

=========================================================

Comments/Suggestions/Errors. Please write to .

Suresh Ranga

skranga2011@gmail.com

8th May 2011.

(No Copyrights on this document, Please use freely)

=========================================================

Apache on Ubuntu. Install/Uninstall

=> i like to change to root, though this is not recommended. please use sudo.

skranga@ubuntu:~$ sudo bash

[sudo] password for skranga:

=> get the version of ubuntu

root@ubuntu:~# cat /etc/issue

Ubuntu 10.10 \n \l

=> install apache now (please add sudo before the command if you are running as root. Please be patient it can take time to install the software, on a slow connection.

root@ubuntu:~# apt-get install apache2

Reading package lists... Done

* Starting web server apache2 [ OK ]

Setting up apache2 (2.2.16-1ubuntu3.1) ...

Processing triggers for libc-bin ...

ldconfig deferred processing now taking place

=> Open a browser and enter http://localhost

If Apache is installed successfully you should see something like this

It works!

This is the default web page for this server.

The web server software is running but no content has been added, yet.

=> How to start, stop and check status of the Apache Server.

root@ubuntu:~# /etc/init.d/apache2 status

Apache2 is running (pid 13872).

root@ubuntu:~# /etc/init.d/apache2 stop

* Stopping web server apache2 ... waiting [ OK ]

root@ubuntu:~# /etc/init.d/apache2 start

* Starting web server apache2 [ OK ]

root@ubuntu:~#

=> How to uninstall Apache. I selected no in the below example. You should select Yes if you wish to uninstall it.

root@ubuntu:~# apt-get remove apache2

Reading package lists... Done

Building dependency tree

Reading state information... Done

The following packages were automatically installed and are no longer required:

apache2-mpm-worker libapr1 libaprutil1-ldap apache2-utils apache2.2-common libaprutil1-dbd-sqlite3

apache2.2-bin libaprutil1

Use 'apt-get autoremove' to remove them.

The following packages will be REMOVED:

apache2

0 upgraded, 0 newly installed, 1 to remove and 323 not upgraded.

After this operation, 36.9kB disk space will be freed.

Do you want to continue [Y/n]? n

Abort.

Prince of Persia

I am not talking about the movie. I am talking of the game that we used to play on DOS. Some of us still like to play this game. But unfortunately our Mac’s and Windows would not run it for us. So how do we do it?

There are two ways.

1. If you are using VMWare then you need to download a VMAppliance, called Nostalgic and run. Your favourite games are all there. Now click here to know more about the appliance.

2. But for lesser mortals there is another way if you are not running VMWare. You need a DOS emulator. DOSbox is the solution. Go to this place and download the DOSBOX. 0.74 is the latest stable version. Next download your game, in our case Prince of Persia from here. With a little effort you can locate more games.

So it’s time you need to rush and rescue the princess.

E-Books Converter

Many of us like to collect e-books. Most of them are in PDF format. But if you are the person who like to read the e-books on other devices like, iphone, android phones, tablets, nokia phones etc, then you might want to convert the books to a format that is friendly with the form factor (screen dimensions) of the device.

There is one excellent software, I recommend highly, called calibre.

So what to do now?

a. download the software from here.

b. Install and run it.

c. Select a PDF. Convert it to epub format. Use iTunes, and bring the epub to iphone, and read it there.

A good place to start is with the hundreds of manuals in PDF format that we read everyday.

Browsers maturing.

So finally customers are having an upper hand while surfing internet. All these years, we had no choice. The browsers were driven by companies needs and less by privacy. It was not un common for sites to collect information with or without our consent. And the list of browsers was very much limited.

Firefox 4 and IE 9 have finally passed the control to us. The basic question is now like this.

a. Do we want sites to collect information on what we are doing on the net? Obviously the answer is NO. These two browsers allow us to browse freely. At least we are not bothered on who is tracking our movement.

b. Do we want Ads to keep coming up when and where we like? Definitely NO again. These two browsers let us do this. Try surfing any site, news paper, blogs, e-commerce and a host of sites with videos come up and running. And you are in a meeting, and this video starts to play with audio.

What about other browsers? Safari, Chrome etc etc. They are not yet there. So what should you do next.

a. Update your browsers if you are using IE or Firefox.

b. Move to these browsers if you are using others.

And drill down and make your settings. If you want to know how, then I will post that too.

Manoj Purohit - Rest In Peace

It has been an extremely sad today today. My cousin brother and a dear friend, Manoj Purohit passed away. We stayed together in 1994. I stayed at their place when I had shifted to Mumbai looking for a job. We used to go together to the town. And then for the next couple of years, I stayed a stone's throw from his house. We spend quite a time together.

And he got married, got a son. And all the time we were together. I left Mumbai in 1998 and then it was a touch and go meeting. The last time we met together was in 2010. That time I had been to his place, and we had dinner together.

He never expressed any feeling outside. He took everything to his heart. After my Aunty passed away in 2003 he took the loss to his heart. He did his business. He achieved a lot of success and made a lot of money as well.

I pray for his soul. And God give strength to his immediate family on this great loss. Bye Manoj.