A completely incomplete guide to computer basics - PART1 Intro: the computer

2020/10/29
code, guide, computer
The first step to solve a problem is to understand what the problem actually is, which is really hard. But nevertheless, let's start by setting up some clear definitions, and try not to mix them up along the way.

• The definition of a computer

The basics of computer are really simple, once you understand what a computer is, and what a computer does. But this actually makes the problem seems harder: "So what is a computer?"

The rabbit hole actually goes pretty deep, so there's a list of definitions on the front:

• Intro: the computer (this one)
• Hardware: process unit
• [TODO] Hardware: memory & disk
• [TODO] Software: code as text
• [TODO] Software: running code
• [TODO] Software: file system
• [TODO] Mixed: device & driver
• [TODO] Software: network
• [TODO] Software: operating system
• [TODO] Mixed: server & virtual machine
• [TODO] Software: be the coder

The definition of a computer

Is it a calculator, a phone, or a computer, and how useful do a computer needs to be?

In 2020, we see and use computers every day, but without realizing some devices are small computers in disguise. One example is the SIM card, a tiny computer operating inside your phone, a much bigger computer. It computes, it saves, and it loads, so it's a computer. By this standard, many modern electric calculator are also computers, but are all calculator computers, head scratch, probably not by today's standards.

Today, in 2020, the standard to qualify as a computer is still quite low, you just need to have:

• a process unit, to compute and calculate, of course!
• some memory, to fast serve and hold hot data went to the process unit
• an optional storage, to hold data for a long time, like hard drives, but some system works fully online and keeps nothing
• an optional display, a common output device to watch movie and play game, if you just want it to do work, then sometimes it's not required
• some optional input device, like the keyboard & mouse combo, or a trackpad
• an optional battery, wait, that's for phones and laptops, scratch that

So a small SIM card is definitely a computer, but no one will call the much bigger modern CPU chips a computer, nor the early big bipolar transistors, computer is like animals, it's not about size, but about living.

How does a computer live its life? Often by consuming a lot of electricity, and producing a lot of heat. And will a computer die? Of course, some broken wire on the board, or a busted fuse will often kill a computer, and same data corruption will also kill it, mentally.

But seriously, as smart as modern computer may seem to be, it's technically very consistent, or non-random. All it does is respond to input with some sort of output, albeit very quickly. Without outer input from user typing, the network packet, or the hardware random number generator collecting thermal noises, a correctly working computer should produce same output for same input, always, unlike asking a question twice to a human.

So to wrap up simply, on the outside a computer is made of chips, and the inside a bunch of bytes. That's what we call "hardware" and "software", we should start define some "hardware" in the following part.