Материал готовится,

пожалуйста, возвращайтесь позднее

пожалуйста, возвращайтесь позднее

So in this section I'm going to talk right

at the smallest level inside of the

computer at individual bits and bytes. So,

a bit in a computer is the smallest amount

of storage that you can have, like an

atom. So a bit just stores a zero or a

one. Those are the only two states it can

do. So you may have heard the expression,

oh well, in computers, you know, it's all

zeroes and ones. That's referring to bits.

Everything in the computer is built up out

of this larger and larger collections of

these simple bits which is just zero and

one. So In the hardware, Anything that

can, is capable of taking on two different

states and when it takes on one state it

can stay in it. That's how you can

represent a bit in hardware and there's a

bunch of different ways of doing it. I've

actually just as a prop. I built this bit

here. So this is a bit made out of a

tennis racket with some plastic in it. And

the way this works is that it has two

different states. So I'm gonna just call

the state the zero state, and then I can

push it to the other state. The plastic

snaps and it stays, we'll call that the

one state so I could switch it back to

zero. Zero, turn around, there's one. So,

it's a trivial example but at the hard

rail of it shows, we have few have two

different state and its stable. When you

put it in a state, it stays. That's enough

to represent a bit in the computer and we

see different forms of it so with the

transistor, the two different states are

done by having little tiny groups of

electrons. On the hard drive platter the

two different states are done by having

either a little area set to either North

magnetism or South magnetism and later can

come back and look, you know just say oh

well, we'll say if it's North, that's a

one and if it's South, it's zero or

whatever. So, the bit just by itself, it's

too small to be good for anything. It's

just, you know? Zero and one, So, really

what we're gonna do is to group eight bits

to make a byte. And the byte is just this

very common unit of measurement. So, if an

example byte is written out, I sort of

think about it like this. Like well,

you're gonna have eight digits but the

digits are binary so each one is just a

zero or a one. And so, any eight, any byte

we could think of is just gonna be this

pattern of eight 0's or 1's. As I

mentioned before a byte in the real world

you can think of it as sorting kinda one

type letter so it's really, it's pretty

small. It holds, holds very little but we

can you know build up other measures out

of it. So the question I wanna look at is.

Exactly how much can one byte hold? And I

wanna work out the math for that. Now I'm

not gonna hold everyone responsible for

the details of this but I wanna go to the

derivation just so you can see it. So

the question I'm going to explore is, if I

have a number of bits, how many patterns,

hHow many distinct patterns can I make with

those bits? And I'm gonna; first of all

just consider either one bit, two bits, or

three bits. So I, I've put these in a

little table. So if I have one bit, I'm

gonna say, this one you could do on your

head. There's just two patterns. Either

it's a zero or it's a one. There's no

center pattern and that's it, two is all

we can do. So supposed we've got two bits so

I'm gonna imagine putting the two bits

next to each other so there's like a left

bit and a right bit and then we can work

at the smallest level inside of the

computer at individual bits and bytes. So,

a bit in a computer is the smallest amount

of storage that you can have, like an

atom. So a bit just stores a zero or a

one. Those are the only two states it can

do. So you may have heard the expression,

oh well, in computers, you know, it's all

zeroes and ones. That's referring to bits.

Everything in the computer is built up out

of this larger and larger collections of

these simple bits which is just zero and

one. So In the hardware, Anything that

can, is capable of taking on two different

states and when it takes on one state it

can stay in it. That's how you can

represent a bit in hardware and there's a

bunch of different ways of doing it. I've

actually just as a prop. I built this bit

here. So this is a bit made out of a

tennis racket with some plastic in it. And

the way this works is that it has two

different states. So I'm gonna just call

the state the zero state, and then I can

push it to the other state. The plastic

snaps and it stays, we'll call that the

one state so I could switch it back to

zero. Zero, turn around, there's one. So,

it's a trivial example but at the hard

rail of it shows, we have few have two

different state and its stable. When you

put it in a state, it stays. That's enough

to represent a bit in the computer and we

see different forms of it so with the

transistor, the two different states are

done by having little tiny groups of

electrons. On the hard drive platter the

two different states are done by having

either a little area set to either North

magnetism or South magnetism and later can

come back and look, you know just say oh

well, we'll say if it's North, that's a

one and if it's South, it's zero or

whatever. So, the bit just by itself, it's

too small to be good for anything. It's

just, you know? Zero and one, So, really

what we're gonna do is to group eight bits

to make a byte. And the byte is just this

very common unit of measurement. So, if an

example byte is written out, I sort of

think about it like this. Like well,

you're gonna have eight digits but the

digits are binary so each one is just a

zero or a one. And so, any eight, any byte

we could think of is just gonna be this

pattern of eight 0's or 1's. As I

mentioned before a byte in the real world

you can think of it as sorting kinda one

type letter so it's really, it's pretty

small. It holds, holds very little but we

can you know build up other measures out

of it. So the question I wanna look at is.

Exactly how much can one byte hold? And I

wanna work out the math for that. Now I'm

not gonna hold everyone responsible for

the details of this but I wanna go to the

derivation just so you can see it. So

the question I'm going to explore is, if I

have a number of bits, how many patterns,

hHow many distinct patterns can I make with

those bits? And I'm gonna; first of all

just consider either one bit, two bits, or

three bits. So I, I've put these in a

little table. So if I have one bit, I'm

gonna say, this one you could do on your

head. There's just two patterns. Either

it's a zero or it's a one. There's no

center pattern and that's it, two is all

we can do. So supposed we've got two bits so

I'm gonna imagine putting the two bits

next to each other so there's like a left

bit and a right bit and then we can work

Загрузка...

Выбрать следующее задание

Ты добавил

Выбрать следующее задание

Ты добавил