HOW A COMPUTER WORKS
by Jim Atkins 'thedosmann'
Over the next few weeks I will write a four part series on "How a Computer Works". I realize this has been covered many times before but it never hurts to have another perspective. I will try and write these articles as non-technical as possible and hope you enjoy the series and that you will find it informative. The four part series titles are as follows:
In this first article we will take a look at what happens when we first turn a computer on. From the power surging into the computer's vein to the CPU waking up.
The CPU and the Rest of the Crew
In this second article we will examine how a CPU works and other major computer components like the monitor, video, keyboard, mouse, sound, and other components.
"What We Have Here Is Failure to Communicate"
In this third article we will discuss how a computer communicates with itself, other components, and how programs talk to the computer.
Is There Any Body Out There?
In this last article of the series we will look at general computer operation including programming, software, networks, and the internet.
I will publish these in my blog and as each one is published a link will be added to the above list. This introduction will be added to each article in the series.
Ready, Set, Power On
Part 1 in a 4 Part Series
Fluid Based Computers
To start off this series, on how computers work, lets first discuss what a computer is. In its purest definition a computer is any device or object that receives information in and then will present an output based on that information. An abacus could be considered a rudimentary computer in that it takes the information, the specific movement of the beads, and gives an output, the final position of each bead corresponding to what bar it is on.
Another basic computer is a calculator because it accepts input and then provides an output based on that input. One other example of a computing process important to remember as we go forward is a dam. A Dam will accept input, the water flowing in from the reservoir, and will present an output based on a predetermined set of conditions. The output can be anything from a set volume of water flow to a generation of power based on that water flow and other set conditions or processes initiated and dependent and controlled by that water flow.
To grasp how Dams relate to computers you should be aware that there are computers that have been built using only fluids; no electricity. Computers have been built using just water or some other fluid media and/or compressed air. The key to doing this is a series of dams or on/off switches that route the media through different channels and at varying volumes and pressure. The 'fluid computers' will have various reservoirs and channels for the fluid to run through and by increasing, stopping, storing, and allowing, flow in certain paths allows it to do complex computations. I will not go into much depth about these devices but having a general concept of their existence will help in understanding computers in general.
When you turn on a computer a lot of things happen all at once. Depending on the type of computer, portable or AC powered, the first process is a conversion of power. A computer plugged into to an AC outlet will first convert that AC power to DC power. The difference between AC power and DC power is an important aspect of overall computer operation. DC power allows the flow of power in an on/off or negative and positive power charge. With a laptop or battery powered computer there is no power conversion because it is already DC powered.
When this DC power begins to flow throughout the circuits in a computer it begins the process of storing, channeling, and directing, the flow and pressure of that power. Without getting too technical, the circuits in a computer have several components that determine the amount of power (Dc Volts), the strength or speed of the flow of power (DC Amps), and the capacity or reserve of that flow. The capacity or amount of flow can change throughout the circuits because some components need less or more volume or differing amounts of strength to operate correctly, this is called resistance. Using these three factors, volts, amps, and resistance, a computer circuit can produce a predictable outcome to countless solutions.
Capacity in circuits is sometimes hard to understand. One way to visualize this is to use the dam as an example. Imagine a river with a dam that channels the water into millions of reservoirs. Each reservoir will have several other dams with gates open to varying degrees or closed that connect to other reservoirs or to each other. Having the dams in certain configurations, or circuits, is what makes a computer work. Changing one gate in one dam will cause a cascade of events with a predictable and measurable outcome.
Once the power is turned on and all the power reservoirs are full the computer is in a ready or in an on state. During the powering on, one component received a lot of special and fine-tuned attention. It has more reservoirs of power, although small, then all the other circuits together- the CPU. In my next article in this series we will take a look at the CPU and other major computer components.
Don't Forget the Working Man
Electrons are what causes the power to flow. Negatively charged electrons are attracted to the positively charged and will flow in that direction. This natural flow of energy can be manipulated through the application of various circuits which result in a solution based on the configuration of the circuit. It suffices to know that as power flows it can be measured and defined based on certain mathematical principals that allow interpretation based on the solution and final product or effect.
A clearer way to understand this is to apply the same principles used in programming. (If x==y then a =b) Programming principles are based on the same algorithm of defining and then interpreting electrical circuits. So when the CPU comes to life it has the circuits in place to interpret the millions of electrical signals it is receiving from all the other computer circuits.
In our next article "The CPU and the Rest of the Crew" we will take a closer look at the CPU and other computer components and how they interact.
by Jim Atkins 'thedosmann'