Microsoft and IBM PC History

No matter how many times I read this story, it never gets boring to me. I finished reading a two part article on Microsoft and IBM PC history featured in Ars Technica UK.

If you are programmer working in this industry, go ahead and consume those pieces. You will turn out a bit more enlightened at the end.

Science of Abstractions

Fundamentally, computer science is a science of abstraction — creating the right model for thinking about a problem and devising the appropriate mechanizable techniques to solve it. - From a Ullman book.

Abstraction is not a complex concept. And abstraction in the sense we use it implies simplification, the replacement of a complex and detailed real-world situation by an understandable model within which we can solve a problem. That is, we “abstract away” the details whose effect on the solution to a problem is minimal or nonexistent, thereby creating a model that lets us deal with the essence of the problem.

Computer Bugs - Roundoff Error and the Patriot Missile


  • During the Gulf War in 1991, a U.S. Patriot missile failed to intercept an
  • Iraqi Scud missile, and 28 Americans were killed.
  • A later study determined that the problem was caused by the inaccuracy of the binary representation of 0.10.
  • The Patriot incremented a counter once every 0.10 seconds.
  • It multiplied the counter value by 0.10 to compute the actual time. However, the (24-bit) binary representation of 0.10 actually corresponds to 0.099999904632568359375, which is off by 0.000000095367431640625.
  • This doesn’t seem like much, but after 100 hours the time ends up being off by 0.34 seconds—enough time for a Scud to travel 500 meters!
  • Professor Skeel wrote a short article about this.

Scale of 256bit security

This video titled How Security is 256 bit security attempts to give a sense of scale as we can understand. The context of this is Bitcoins which have SHA256 as the crypt algorithm. Other alt-coins have different algorithms for their crypts.

Compiler Design Concepts in Tamil and Hindi

I came across this Youtube channel, wherein a person by name Santhosh is explaining very hard to understand Compiler Design Concepts in Tamil

His playlist is here

I also came across compiler design lecture explanation in Hindi by a different people.

These are hard concepts. Even after reading the book, if I am struggling to understand; viewing these videos seems give a comfort and confidence. Something to say about the languages that we grew up with.

Running Reboot.

On June 4, 2017, I have resumed my practice of running. Did my first jog in the morning. If my chain breaks, I plan to provide my update with a post and reason why it broke.


I like this anarchist movement of digital crypto-currency. People are betting on algorithms!

I spent time looking around and found that I liked, the concept of mining with hashpowers and effort that has gone into setting up cloud mining companies like and exchanges like

Trying with seems only like an entry point to this messy world.