Crazy Things About Your Computer You Never Knew!

It’s a ritual across the globe: somewhere

between sticking the kettle on and

complaining about last night’s match,

you’ll probably click the button on your

ageing company Personal computer and wait while it

slowly thinks about turning on. Rather

than take it for granted, though, it’s

worth taking a couple minutes to realise

a few of the things that your poor robot

slave does without you ever knowing.

Everything you see or hear

on the internet is actually on

your computer

All your computer-whizz friends

probably delight in telling you how

having a ‘library’ of videos is so 2008,

that no-one torrents any more, it’s all

Netflix and iPlayer and ‘The Cloud’,

whatever that means. But, you might

want to remind them: every time you

stream a video or the week’s latest Top

40 off the web, it’s actually, technically

playing off your computer.

See, every internet media file has to

make a local copy of itself on your

machine, first. Ever wondered what

that white buffering bar means on

YouTube or Netflix? It’s the amount of

video that’s been copied to the local

cache, a.k.a. the amount you can still

watch if your internet decides to up and

die.

Counting Starts at Zero

At a base level, every computer’s just a

really big, complicated calculator. But

thanks to the way its intrinsic circuitry

works – with lots of little logic gates that

are either ‘on’ or ‘off’ – every action

that takes place at a base level is

happening in binary, where things are

either a 1 or a 0, with no shades of grey

in between.

This actually translates up to a neat bit

of programming trivia – in the computer

science world, all counting (with the

rather notable exceptions of Fortran

and Visual Basic) starts at zero, not

one.

It actually makes a lot more sense –

ever thought about why the 20th century

refers to the 1900s? It’s because when

historians decided on the dating

system, they weren’t clever enough to

call the very first century (0-99AD) the

0th century. If they had, we’d probably

have far fewer confused school children

the world over.

Bits, Bytes, and Size

Next time you complain about the pitiful

memory capacity of your old 8GB iPod

Touch, it’s worth remember what makes

up eight whole gigabytes. Computer

science grads will know that in every

gigabyte, there’s 1024 megabytes; 1024

kilobytes in a megabyte, and 1024 bytes

in a kilobyte. Breaking it down to the

lowest level, you’ve got 8 bits in a byte. Even a floppy disk has a fair few of

these

Why does that matter? Because on a

flash drive, each bit of data is made up

of eight separate floating gates, each

comprising two physical transistors,

which can basically record themselves as

either a ‘1’ or a ‘0’. (Want to be

impressed ever further? Each floating

gate actually relies on quantum

mechanics to work.) That means that an

8GB iPod Touch – the one you were

laughing at a minute ago for being puny

– has, according to my back-of-the-

napkin maths, 549,755,813,888

individual gates arrayed inside that

svelte aluminium body. Mighty clever

engineering indeed.

The distance data travels

A quick experiment for you: click this

link, which should take you to Wikipedia.

With one click, you’ve just fetched a

bunch of data from servers in Ashburn,

Virginia, about 6000km away. Your

request has travelled from your

computer, through a local Wi-Fi router

or a modem, up to a local data centre,

from there onwards (under the Atlantic

Ocean, if you’re in the UK), all the way

to Virginia, and back again – in around

0.1 of a second, depending on how good

your internet connection is By comparison, your body takes around

0.15 of a second for a signal to pass

from your fingers, up your spinal cord

to the brain, and back down again.

The work that goes into a

Ctrl+C, Ctrl+V

One rather under-appreciated fact

about solid state drives (SSDs),

regarded as the gold standard for fast,

reliable storage, is the amount of

copying they have to do. When you want

to copy some data from one bit to

another, it’s not just a matter of

shuffling the data from one part of the

drive to another.

Because of the complicated way a SSD

works , over-writing a block of old data

with some shiny new data isn’t as simple

as just writing the new stuff in with a

bigger, thicker Sharpie. Rather, the

storage drive has to do some

complicated shuffling around.

No-one ever accused SSDs of being too

simple  In practice, this can

that writing

a tiny 4KB file can require the drive to

read 2MB (that’s thousands of times

more data that the 4KB file you’re

trying to write), store that temporarily,

erase a whole tonne of blocks, then re-

write all the data. It’s rather labour-

intensive, so think before you juggle

your files around next time.

Code isn’t as clean as you

think

The majority of us put faith in bits of

technology you don’t quite understand –

be it committing your life to a 747, or

your dirty pics to Snapchat’s auto-

delete. When you do you generally tend

to assume that the code’s been

scrupulously examined by teams of

caffeine-fuelled programmers, with

most of the niggling little bugs found

and nixed.

The truth seems to be quite the opposite.

One Quora user pointed out that buried

within the source code for Java, one of

the internet’s fundamental bits of

code, is this gem:

/**

* This method returns the Nth bit that is

set in the bit array. The

* current position is cached in the

following 4 variables and will

* help speed up a sequence of next()

call in an index iterator. This

* method is a mess, but it is fast and it

works, so don’t fuck with it.

*/

private int _pos = Integer.MAX_VALUE;

It just goes to show that even

programmers rush things to get home

for the next installment of Game of

Thrones sometimes.