Simple But Nerdy

In the previous posts I highlighted the various concepts that are fundamental to designing a computer. Now I think its time to mention the ways of practically applying these concepts to design a computer. The first thing I should highlight is that I will not be using transistors, I'll be using relays. This is due to the fact that its easier to understand how a relay works than to understand how a transistor works. Also, this seems to be the easiest way to understand how computers actually work since we are using mechanical switches instead of solid state switches (transistors). What is a Relay?? Relays are basically electrically controlled switches. Inside a relay is an electromagnet. when the electromagnet is powered, it attracts a metal strip that in turn operates a switch. Most widely available relays are SPDT relays or Single Pole Double Throw relays. In these relays the switch has 3 terminals- Common terminal , NO i.e. normally open terminal and NC i.e. normally ...

I remember studying about logic gates for the first time in a computer class in school, AND, NAND, OR, NOR, NOT, XOR gates. It sounded like the stupidest thing I had ever learnt. Added to that it was too easy to even be worth teaching. And why would anyone teach it in a computers course anyway?? Has it got anything to do with computers?? The answer, Yes, it has everything to do with computers. The fact that a digital computer exists is because of logic gates. All of the decisions a computer takes and the tasks a computer does are dependent on logic gates. It was only in college during my Digital Electronics course did I finally recognize the power of logic gates. Although its self explanatory, let me first explain what a gate is. A gate is a device that allows an event to happen. It controls when the event happens and for how long that event happens. For eg. the switch acts as a gate for the light bulb since its operation determines when the light is switched ON and for how ...

For quite a while I have been trying to come up with a way to explain how the binary number system works, because its not really an intuitive way of dealing with numbers. If counting numbers is so easy why make such a complex way of dealing with them in a computer?? the answer is its easy to represent something in terms of ON or OFF than to have 10 different levels for representing the numbers. From a very young age we are taught about numbers and how to count them. But learning that we have just accepted certain rules such as, Zero is written as, '0' One is written as, '1' Two is written as, '2' Three is written as, '3' and so on.... If you think about it, these are just arbitrary symbols given to numbers from zero '0' to nine '9'. We have gotten used to calling these symbols as numbers that we don't realize this fact. In our number System we have symbols from '0' to '9' i.e. ten symbols for ten n...

JUST A RANT.... While learning about things in school, I believe, we have developed this habit of learning things for the sake of learning them i.e. learning without context. This, I believe, causes one of the two things, we either feel that we do not have the intellect to understand how something works, or we feel we know all that can be known. Everything ever taught is so vague that its almost useless. take for example what we are taught about computers: we know a CPU (Central Processing Unit) has 3 parts; ALU (Arithmetic and Logic Unit), CU (Control Unit) and memory. Yet all we know about them is their full forms and a one line description of their role in a computer. We know that computers understand machine language and that machine language is a bunch of 1's and 0's but no one really explains how does that happen. So, for most people a computer is just a magical black box. They command it to do stuff and that box does it. Let's talk computers: For almost...