Trying to figure out how a computer works can be daunting, not necessarily because it’s too complicated, but because it’s really easy to get sucked into a black hole of technical specifications filled to the brim with undecipherable jargon. I’m looking at you, Wikipedia.
Fortunately, you really don’t need to know all the gory details about the 7 layers of network abstraction or the specific x86 processor instructions to understand how a computer works. I sure as heck don’t. So this series of posts aims to provide a working knowledge of what makes a computer compute.
Alright, let’s jump into it with a quote from the MS-DOS 5.0 Manual1User’s Guide and Reference for the MS-DOS Operating System Version 5.0, copyright 1991 Microsoft Corporation to the first computer I used2and if you’re laughing at my practically modern beginnings, well, this post isn’t meant for you anyway 🙂. No, no, wake back up and hear me out…
Your computer is made up of many parts called hardware. Your hardware runs software – programs that translate the instructions you send to your computer into a language it can understand.
So, Hardware and Software. Two completely useless things on their own that only become useful when used together. The quote also makes another key point: software is a translator between you and the hardware. This post is going to focus on the hardware portion, but keep that fact in mind for future use. So, let’s start with the hardware!
The Desktop Metaphor
Imagine yourself working at a desk on some paperwork. Except, you’re really tired all the time and you can’t think critically. All you can do is follow directions. Also, the cleaning crew is merciless and will cleanse your desk with a flamethrower as soon as you leave. This is a computer!
The CPU: You
When you’re working, you’re working. You move the papers around, read their instructions, and fill them out accordingly. Unsurprisingly, the faster you read and write, the more paperwork you can get through.
This is the role of the Central Processing Unit (CPU, or just Processor) in your computer. It is the main brains; nothing happens without going through the CPU first3Ok, there’s a few things that get done without the CPU getting involved. But those special cases are a whole ‘nother blog post.. It reads data from the other parts of the computer, follows the given instructions to either change or create new data, and sends it to another part of the computer. A faster CPU will be able to process more instructions in a given time.
The RAM: Your Desk Space
When you work on the paperwork, you have it out on your desk. Easy enough. More difficult instructions need information from other papers too, so naturally you spread all the papers out on the table while you’re working. Now you get an important new task, so you spread those papers out too. But if you’re out of desk space, you’ve got to make room by putting the less important tasks into a pile somewhere else. If you change tasks again, you have to go through the pile and find the relevant papers before you can work again which takes time. The moral of the story: The bigger your desk, the more things you can do at once.
This is the role of the Random Access Memory (RAM, or just Memory) in your computer. The RAM is fast, temporary memory that holds instructions and other information for the CPU. Having more RAM will let your computer keep more programs up and ready for your use.
The Hard Drive: The Filing Cabinet
The cleaning crew is ruthlessly efficient with their unholy flame, so as soon as you’re done with your task, you’d better put it away in the fireproof filing cabinet so you can find it later. Then you find the next file you need and make a copy for your desk. It should come as no surprise that the faster you’re able to find and put away files, the faster you can start and finish your tasks.
This is the role of the Hard Drive (or Disk drive) in your computer. It’s the slow, long-term memory that stays around even when it loses power. You see, RAM needs electricity to work, so anything stored in RAM when the computer is shut off gets lost permanently. Anything you want between power cycles can only be saved on a hard drive.
So, that’s a look at the major hardware components of a computer. I’ll be referencing this analogy throughout these next few posts, so hopefully it helps. Of course, there’s plenty more components in the computer, but I’ll get to those later.
So if someone ever tells you to “download more RAM”, kindly remind them that you can’t download hardware and punch them square in the mouth. Politely, of course.