The Least Necessary to Know About Computers
Introduction
The disagreement
My 8 year old, Bash, and I have some disagreement on what a computer is. He tells me a computer doesn’t have a touchscreen—those are for phones and tablets. He’s not too sure about his Nintendo Switch video game console, but he doesn’t think so; it doesn’t have a keyboard and you can use its touchscreen as well—definitely NOT a computer.
I tell him even my coffee machine is a computer. It is one if those fancy automatic espresso makers—with a touchscreen. I tell him it executes specific instructions, repeating them each time I ask it to make me a coffee, and it was programmed just like the computer on my desk. His face is filled with doubt.
I ask him, ok, then what is a computer? He doesn’t seem quite as sure as when we started this conversation, but he knows it doesn’t have a touchscreen. It seems I have just confused him, but I’m still really confident I know the right answer—I just need some time to put it in the right words.
The motivation
Why do I care so much he knows what my definition of a computer is anyway? Doesn’t he already know computers impact almost every aspect of your daily life? From moving your money and moving your car, to moving your emotions and moving your social status, the world is just short of being moved entirely by computers. Does he realize this?—Sure he does.
Venting to one of the other baseball dads about how our kids should be taught some basics glossed over by our educational system, the dad agrees a course on common sense should be mandatory—you know, like how to change a tire! Yeah, I say! Configuring a wireless router and changing a tire.
It comes to me that we all have our own ideas about what qualifies as common sense. Figuring out what is critical to know for people today isn’t easy. Sitting in traffic, I imagine a driver sitting on the side of the road, picking up their mobile phone and calling AAA, just like my mother-in-law calls me when her printer isn’t “showing up”. Does she really need to know how to reset her router to overcome an flooded DHCP table? I’m not sure, but at least she knows what a tire is, why it might not be holding air and what it means for someone to swap it out with a tire that will hold air. Perhaps being able to change the tire isn’t the goal, but I’d feel better about anyone driving a car if they knew what a tire was and why it is important to the operation of that car.
AI. Bad code. boot times.
The cloud is a place.
All memory is both permanent and temporary, it is the level of effort to recover that changes.
A computer is a data processing machine
Data is always volatile and non-volatile “oh how easy we forget”
Its all sensors and actuators. We used to call these inputs and outputs.
What is and is not a computer?
Bash’s Definition
What is a computer?
A computer is a machine that can be programmed to translate words into 0s and 1s and can be made into different things, like a robot or a self-reading book. Anything can have a computer.
Human computers
Mechanical computers
Embedded computers
Analog computers and state machines
Computers do exactly what they are told
Computers process inputs and generate outputs
Computers remember everything, except what they forget, so make backups
What is volatility?
What
Memory is really another type if input and output
Data recovery
There is no cloud, the network is not the computer
What makes a computer smart?
A computer is a machine
Bash’s Definition
What is a machine?
A machine is a system that uses different power [sources], like coal, fire, contraptions, and chain reactions.
I feel like I should have started by asking about the definition of “work”. From the viewpoint of a physicist, “work” is the transfer of energy with an object along a line, or displacement. A machine changes the direction or magnitude of a force, making things more interesting.
If I move an object from one place to another, I’ve done “work” in the eyes of a physicist. An employer or parent might decide that the work I did wasn’t all that useful or might not call it work at all, but might instead call it making a mess. Still, I transferred energy, from blood, to my brain, to the muscles in my legs and arms, and finally to that ball that I took out and left in the living room.
The forces I applied didn’t all go in the same direction. My muscles contracted in one direction and the joints, and the floor, moved my arms and legs in another.
I am a machine!
A computer is a machine too. A computer won’t do anything without energy. I’d say that a computer is only a machine.
What is not a computer?
Bash’s Definition
Are there machines without computers?
Yes, there are machines without computers and they are called simple machines, for example, brooms, levers, wedges, wheels and axles, pulleys, and screws.
If a computer can be so many things, maybe we should start by describing what is not a computer.
Back in the 1980s, I met a really cool robot called 2-XL. 2-XL has a very engaging personality and an amazing sense of humor. And 2-XL was smart, it knew history and science. It could make me laugh and it fed my interest in learning. I really like 2-XL and I miss it.
2-XL is not a computer.
But hey, wait, didn’t I say robots were computers and 2-XL is a robot? Yep, I said both of those things. I cannot honestly say which one of them is wrong. Mind you, 2-XL is not your typical robot. 2-XL is basically a glorified 8-track player.
Does that mean an 8-track player is a robot?
For most of you that don’t know, an 8-track player is like a cassette player, but where the tape is continuous and runs in a loop. You can also move the head that reads the tape to 4 different positions, enabling you to hear one of four different stereo recordings sitting side-by-side on the tape. Each recording, being stereo, meaning you have different audio for each of your two ears, takes up two tracks, or lanes on the tape where the magnetic charge on the tape sits with different intensities representing the audio. Four different 2-track recordings give the player its name, an 8-track player. And for those that don’t know what a cassette player is, well, it’s a crummy version of an 8-track where you only have 4 tracks on the tape and you have to run the tape backwards when you reach the end to hear the other stereo recording. And, naturally, most cassette tape players required you to manually eject the cassette and flip it over, because the motors will only turn the tape one direction during playback and the head won’t move to the other track locations–it is just stuck in one place.
For some of you, your heads are spinning trying to grasp the mechanical complexity of a tape player. For others, this trip into nostalgia probably also has you saying, “why didn’t you just explain the simpler reel-to-reel mechanism?” OK. Moving on.
All of this is just to say that 2-XL is an 8-track player with blinking lights for eyes that change with the volume of the audio coming out of it. And 2-XL had 4 red buttons on its belly, one for each of the possible recordings on the 8-track cassette you put into it. This glorified tape player looked like a robot, spoke better than any robot I can imagine, responded to my inputs and had electrical and mechanical innards that moved in response to both me and the recording. Definitely, 2-XL is a robot in my book. At least this book.
2-XL likes to ask questions. Press a button and 2-XL responds if you answered correctly. 2-XL might even keep track if you’ve made previous mistakes and get extra snarky.
2-XL is ingeneous, however, 2-XL is not a computer. Nothing in 2-XL is executing the instructions of a computer program.
Todo
Lots left to elaborate here.
Why are computers important?
Why should computers be important to you?
Changing a computer’s tire
How to configure and reset a router and modem
DHCP
Life threatening computer things?!?
History
Exercises
Wireshark