CPU

HARDWARE

A CPU, is the brain of the computer system, it stands for Computer, Proccesing, Unit.

It works by looking up what to do with the input, for example you press print, CPU, collects the information needed to do it in the  ROM (Read Only Memory) and then stores that temporarily in the RAM (Random access memory) while it is waiting to process it. It then does what it tells it to do, for example prints the paper.

It is super fast at doing this. This is the endless cycle of fetch, decode and excecute. Fetch the information, turn it into binary code, and do the action/output.

Cache memory is often inside the CPU, it is used to store instructions that are used to repeatedly run programs, it is extremely fast and used to speed up the process.

Binary Logic

Binary is just 0's and 1's,  they can be used to represent all numbers.
it is used because they can be represented easily using an on/off state or switch.
computers use logic gates to manipulate the data.

AND GATE
only 1 if there are two 1's

this table shows the inputs and what the output would be

OR GATE
only 0 when there are two 0's

NOT GATE
output is opposite to input

This is what happens when you combine and  then not

ROM, FLASH, VIRTUAL AND CACHE MEMORY

Input and output

We need input and output devices because to make something happen, you need to be able to give it info on what to do, and it needs to then do something.

Possible input devices could be your body, via 3d sensers, our brains. Outputs can be almost anything, like a picture, video, movement, ordering something online.

Input and output devices, can help people with specific needs a lot.  For example we can communicate with Stephen hawking using eye sensers, in the past, their would be no real way of communicating with him.

If you are paralysed, in the future, they could hook you up to a brain sensor and you could communicate that way.

Order stuff online, even be hooked up to some sort of machine, that you could walk around using, and pick stuff up.

Secondary storage

Stores information when the power is off.

There are 3 main types, optical, magnetic and solid state.

We need it because otherwise we would have to upload data every time we turn it on, but using secondary data, the data will stay as it doesn't dissapear over time.

Magnetic storage

Reliable, lots of storage at a low cost, can be internal or external.

Hard drive, normally in the computer itself, most of them have one.

Optical storage

Lots of storage at low costs, small and easy to distribute, they are robust and are normally read only,

Includes CD's and DVD's.

http://www.amazon.co.uk/TDK-CD-R80CBA10-B-CD-R-80min-Spindle/dp/B000A33TD2/ref=sr_1_2?ie=UTF8&qid=1382346135&sr=8-2&keywords=blank+cds

10cds with 700mb each for under £3 or equivalent of 30p each

Solid state

Includes stuff like USB, can be more expensive than other storages, flash memory, fast access times.

Include USB's or memory sticks.

This one costs £20 with 16GB memory space.

http://www.amazon.co.uk/Kingston-Technology-16GB-DataTraveler-DT101G2/dp/B003MWJKVI/ref=sr_1_1?ie=UTF8&qid=1382346591&sr=8-1&keywords=USB

first lesson

What is a computer system?

A computer system is a group of parts that work together to achieve the same goal.
All computer systems have one or more inputs, processes and one or more outputs.

Reliability 

Reliability is where it won't make and error and will always achieve the goal it was intended, so in a game, you gun will always fire in front of you when you fire.

Reliability is important because we heavily rely on computer systems, if a bank one glitches up then you might be left having no money/ a boat navigation system glitches you could crash into rocks / go opposite direction to where you want to go.

Even in the most reliable systems, like space craft, the system could still glitch, that is why there is no such thing as a 100 percent reliable system.

Input, process and output

Input- the information given to the system for example: you pressed left key

process- information is processed using programming and sometimes using information from the
program you are in.

Output- some kind of effect happens, say the gun fires at the zombie

Embedded system

An embedded system is a system designed to carry out a specific set of functions, and is inside the product, for example, it tells the washing machine will always have to clean the clothes depending on what type and how many, whereas a phone has to be flexible so it can react to new functions so it can make a person in this app move forwards when you press the forward key.

Regulations

Regulation exist to protect your information, to protect you from having your identity stolen, to stop people spending all your money. THE DATA PROTECTION ACT says: that your data must be up to date; be kept securely (especially if it goes to another country); be kept only for the time that is needed; be used for a particular lawful reason and be accurate.

several other Acts have been made to keep up with the ever changing technology and the regulations they need. The Computer Misuse Act was made to stop people hacking/ using someone's computer or material without permission or giving it a virus.

Also, some Acts like the copyright one, were made originally for a different purpose but include computers now. Under this Act, you cant copy and sell other people's copyrighted stuff, without their permission.