Hi all,
It's been a while since my last post. I've been trying to come up with more ideas for these posts, but I could not come up with any subject that could be covered in a single post. I feel like the last post was a bit too long, too.
So now I will cover a complex subject by breaking it up into smaller posts. The subject: how computers work. Some people are familiar with the components; to others, the computer is a magic box. Many people have covered the subject from a software point. So many have some idea about programs or apps, and how the OS (Windows, Mac, Linux) executes them.
Being a hardware focused electrical engineer, I'd like to cover this from another perspective. I will start from the most basic building blocks and build our way up, focusing on the processor (the computer's brain). Because when it comes right down to it, a computer is a complex coordination of simple switches. Yup. Thats. It. Again, keep in mind that the topics are extremely simplified. If you'd like more accurate details or want to suggest some corrections, please contact me.
PART 1: STATES
So for this first segment, I will cover a background subject: states. States, in this case, refers to "the condition of a person or thing, as with respect to circumstances or attributes: a state of health" (Dictionary.com). What does this mean? In plain terms, any object is in a particular state given certain inputs, and this state produces an output. For example, a light bulb is in an 'on' state when the switch is in one position. When the switch changes to the other position, the bulb is in an 'off' state. This is a simple state because there is only one input (the switch position), two possible states ('on'/'off') given the input, and one output (light).
How does this apply to computers? Computers do their work based on the state of the processor's elemental building block, the transistor. There are two states, like in the light bulb, with a voltage acting as the input. If the transistor is on, it conducts electricity and produces a current. If it is off, there is no current. The current is the transistor's output. From here, transistors are interconnected to perform certain functions. Some of the outputs act as the inputs of other transistors and so on.
So to recap, computers work through the state of transistors. A state is decided by inputs and produces an output. For transistors, the input is a voltage, the state is 'on' or 'off', and the output is a current.
Tune in soon for the next topic... binary!
